diff --git a/src/js/messaging.js b/src/js/messaging.js
index 44c4e810f..806845c7c 100644
--- a/src/js/messaging.js
+++ b/src/js/messaging.js
@@ -1641,7 +1641,7 @@ const onMessage = function(request, sender, callback) {
 
     case 'temporarilyAllowLargeMediaElement':
         if ( pageStore !== null ) {
-            pageStore.allowLargeMediaElementsUntil = Date.now() + 2000;
+            pageStore.allowLargeMediaElementsUntil = Date.now() + 5000;
         }
         break;
 
diff --git a/src/js/pagestore.js b/src/js/pagestore.js
index 7301f992b..ad80d1ae0 100644
--- a/src/js/pagestore.js
+++ b/src/js/pagestore.js
@@ -244,7 +244,7 @@ const PageStore = class {
             typeof this.allowLargeMediaElementsUntil !== 'number' ||
             tabContext.rootHostname !== this.tabHostname
         ) {
-            this.allowLargeMediaElementsUntil = 0;
+            this.allowLargeMediaElementsUntil = Date.now();
         }
 
         this.tabHostname = tabContext.rootHostname;
@@ -260,6 +260,7 @@ const PageStore = class {
         this.largeMediaCount = 0;
         this.largeMediaTimer = null;
         this.internalRedirectionCount = 0;
+        this.allowLargeMediaElementsRegex = undefined;
         this.extraData.clear();
 
         this.frameAddCount = 0;
@@ -339,7 +340,8 @@ const PageStore = class {
         this.rawURL = '';
         this.hostnameToCountMap = null;
         this.netFilteringCache.empty();
-        this.allowLargeMediaElementsUntil = 0;
+        this.allowLargeMediaElementsUntil = Date.now();
+        this.allowLargeMediaElementsRegex = undefined;
         if ( this.largeMediaTimer !== null ) {
             clearTimeout(this.largeMediaTimer);
             this.largeMediaTimer = null;
@@ -438,7 +440,12 @@ const PageStore = class {
     temporarilyAllowLargeMediaElements(state) {
         this.largeMediaCount = 0;
         µb.contextMenu.update(this.tabId);
-        this.allowLargeMediaElementsUntil = state ? Date.now() + 86400000 : 0;
+        if ( state ) {
+            this.allowLargeMediaElementsUntil = 0;
+            this.allowLargeMediaElementsRegex = undefined;
+        } else {
+            this.allowLargeMediaElementsUntil = Date.now();
+        }
         µb.scriptlets.injectDeep(this.tabId, 'load-large-media-all');
     }
 
@@ -704,7 +711,23 @@ const PageStore = class {
     filterLargeMediaElement(fctxt, size) {
         fctxt.filter = undefined;
 
+        if ( this.allowLargeMediaElementsUntil === 0 ) {
+            return 0;
+        }
+        // Disregard large media elements previously allowed: for example, to
+        // seek inside a previously allowed audio/video.
+        if (
+            this.allowLargeMediaElementsRegex instanceof RegExp &&
+            this.allowLargeMediaElementsRegex.test(fctxt.url)
+        ) {
+            return 0;
+        }
         if ( Date.now() < this.allowLargeMediaElementsUntil ) {
+            const sources = this.allowLargeMediaElementsRegex instanceof RegExp
+                ? [ this.allowLargeMediaElementsRegex.source ]
+                : [];
+            sources.push('^' + µb.escapeRegex(fctxt.url));
+            this.allowLargeMediaElementsRegex = new RegExp(sources.join('|'));
             return 0;
         }
         if (
@@ -713,6 +736,7 @@ const PageStore = class {
                 fctxt.getTabHostname()
             ) !== true
         ) {
+            this.allowLargeMediaElementsUntil = 0;
             return 0;
         }
         if ( (size >>> 10) < µb.userSettings.largeMediaSize ) {
diff --git a/src/js/scriptlets/load-large-media-all.js b/src/js/scriptlets/load-large-media-all.js
index a6d71734a..943706d28 100644
--- a/src/js/scriptlets/load-large-media-all.js
+++ b/src/js/scriptlets/load-large-media-all.js
@@ -19,48 +19,36 @@
     Home: https://github.com/gorhill/uBlock
 */
 
+'use strict';
+
 /******************************************************************************/
 
-(function() {
-
-'use strict';
+(( ) => {
 
 /******************************************************************************/
 
 // For all media resources which have failed to load, trigger a reload.
 
-var elems, i, elem, src;
-
 // <audio> and <video> elements.
 // https://developer.mozilla.org/en-US/docs/Web/API/HTMLMediaElement
 
-elems = document.querySelectorAll('audio,video');
-i = elems.length;
-while ( i-- ) {
-    elem = elems[i];
-    if ( elem.error !== null ) {
-        elem.load();
-    }
+for ( const elem of document.querySelectorAll('audio,video') ) {
+    if ( elem.error === null ) { continue; }
+    elem.load();
 }
 
 // <img> elements.
 // https://developer.mozilla.org/en-US/docs/Web/API/HTMLMediaElement
 
-elems = document.querySelectorAll('img');
-i = elems.length;
-while ( i-- ) {
-    elem = elems[i];
-    if ( elem.naturalWidth !== 0 && elem.naturalHeight !== 0 ) {
-        continue;
-    }
+for ( const elem of document.querySelectorAll('img') ) {
+    if ( elem.naturalWidth !== 0 && elem.naturalHeight !== 0 ) { continue; }
     if ( window.getComputedStyle(elem).getPropertyValue('display') === 'none' ) {
         continue;
     }
-    src = elem.getAttribute('src');
-    if ( src ) {
-        elem.removeAttribute('src');
-        elem.setAttribute('src', src);
-    }
+    const src = elem.getAttribute('src') || '';
+    if ( src === '' ) { continue; }
+    elem.removeAttribute('src');
+    elem.setAttribute('src', src);
 }
 
 /******************************************************************************/
diff --git a/src/js/scriptlets/load-large-media-interactive.js b/src/js/scriptlets/load-large-media-interactive.js
index 44c528c26..a24f1c80e 100644
--- a/src/js/scriptlets/load-large-media-interactive.js
+++ b/src/js/scriptlets/load-large-media-interactive.js
@@ -36,9 +36,10 @@ if ( typeof vAPI !== 'object' || vAPI.loadLargeMediaInteractive === true ) {
 
 const largeMediaElementAttribute = 'data-' + vAPI.sessionId;
 const largeMediaElementSelector =
-    ':root audio[' + largeMediaElementAttribute + '],\n' +
-    ':root   img[' + largeMediaElementAttribute + '],\n' +
-    ':root video[' + largeMediaElementAttribute + ']';
+    ':root   audio[' + largeMediaElementAttribute + '],\n' +
+    ':root     img[' + largeMediaElementAttribute + '],\n' +
+    ':root picture[' + largeMediaElementAttribute + '],\n' +
+    ':root   video[' + largeMediaElementAttribute + ']';
 
 /******************************************************************************/
 
@@ -51,9 +52,7 @@ const mediaNotLoaded = function(elem) {
     case 'video':
         return elem.error !== null;
     case 'img':
-        if ( elem.naturalWidth !== 0 || elem.naturalHeight !== 0 ) {
-            break;
-        }
+        if ( elem.naturalWidth !== 0 || elem.naturalHeight !== 0 ) { break; }
         const style = window.getComputedStyle(elem);
         // For some reason, style can be null with Pale Moon.
         return style !== null ?
@@ -74,50 +73,57 @@ const mediaNotLoaded = function(elem) {
 // https://developer.mozilla.org/en-US/docs/Web/API/HTMLMediaElement
 
 const surveyMissingMediaElements = function() {
-    var largeMediaElementCount = 0;
-    var elems = document.querySelectorAll('audio,img,video');
-    var i = elems.length, elem;
-    while ( i-- ) {
-        elem = elems[i];
-        if ( mediaNotLoaded(elem) ) {
-            elem.setAttribute(largeMediaElementAttribute, '');
-            largeMediaElementCount += 1;
+    let largeMediaElementCount = 0;
+    for ( const elem of document.querySelectorAll('audio,img,video') ) {
+        if ( mediaNotLoaded(elem) === false ) { continue; }
+        elem.setAttribute(largeMediaElementAttribute, '');
+        largeMediaElementCount += 1;
+        switch ( elem.localName ) {
+        case 'img': {
+            const picture = elem.closest('picture');
+            if ( picture !== null ) {
+                picture.setAttribute(largeMediaElementAttribute, '');
+            }
+        } break;
+        default:
+            break;
         }
     }
     return largeMediaElementCount;
 };
 
-if ( surveyMissingMediaElements() === 0 ) {
-    return;
-}
+if ( surveyMissingMediaElements() === 0 ) { return; }
 
 vAPI.loadLargeMediaInteractive = true;
 
-// Insert custom style tag.
-let styleTag = document.createElement('style');
-styleTag.setAttribute('type', 'text/css');
-styleTag.textContent = [
-    largeMediaElementSelector + ' {',
-        'border: 1px dotted red !important;',
-        'box-sizing: border-box !important;',
-        'cursor: zoom-in !important;',
-        'display: inline-block;',
-        'font-size: 1em !important;',
-        'min-height: 1em !important;',
-        'min-width: 1em !important;',
-        'opacity: 1 !important;',
-        'outline: none !important;',
-    '}'
-].join('\n');
-document.head.appendChild(styleTag);
+// Insert CSS to highlight blocked media elements.
+if ( vAPI.largeMediaElementStyleSheet === undefined ) {
+    vAPI.largeMediaElementStyleSheet = [
+        largeMediaElementSelector + ' {',
+            'border: 2px dotted red !important;',
+            'box-sizing: border-box !important;',
+            'cursor: zoom-in !important;',
+            'display: inline-block;',
+            'font-size: 1rem !important;',
+            'min-height: 1em !important;',
+            'min-width: 1em !important;',
+            'opacity: 1 !important;',
+            'outline: none !important;',
+            'visibility: visible !important;',
+            'z-index: 2147483647',
+        '}',
+    ].join('\n');
+    vAPI.userStylesheet.add(vAPI.largeMediaElementStyleSheet);
+    vAPI.userStylesheet.apply();
+}
 
 /******************************************************************************/
 
 const stayOrLeave = (( ) => {
-    let timer = null;
+    let timer;
 
     const timeoutHandler = function(leaveNow) {
-        timer = null;
+        timer = undefined;
         if ( leaveNow !== true ) {
             if ( 
                 document.querySelector(largeMediaElementSelector) !== null ||
@@ -127,9 +133,8 @@ const stayOrLeave = (( ) => {
             }
         }
         // Leave
-        if ( styleTag !== null ) {
-            styleTag.parentNode.removeChild(styleTag);
-            styleTag = null;
+        for ( const elem of document.querySelectorAll(largeMediaElementSelector) ) {
+            elem.removeAttribute(largeMediaElementAttribute);
         }
         vAPI.loadLargeMediaInteractive = false;
         document.removeEventListener('error', onLoadError, true);
@@ -137,7 +142,7 @@ const stayOrLeave = (( ) => {
     };
 
     return function(leaveNow) {
-        if ( timer !== null ) {
+        if ( timer !== undefined ) {
             clearTimeout(timer);
         }
         if ( leaveNow ) {
@@ -160,24 +165,44 @@ const loadImage = async function(elem) {
 
     elem.setAttribute('src', src);
     elem.removeAttribute(largeMediaElementAttribute);
+
+    switch ( elem.localName ) {
+    case 'img': {
+        const picture = elem.closest('picture');
+        if ( picture !== null ) {
+            picture.removeAttribute(largeMediaElementAttribute);
+        }
+    } break;
+    default:
+        break;
+    }
+
     stayOrLeave();
 };
 
 /******************************************************************************/
 
 const onMouseClick = function(ev) {
-    if ( ev.button !== 0 ) { return; }
+    if ( ev.button !== 0 || ev.isTrusted === false ) { return; }
 
-    const elem = ev.target;
-    if ( elem.matches(largeMediaElementSelector) === false ) { return; }
+    const toLoad = [];
+    const elems = document.elementsFromPoint instanceof Function
+        ? document.elementsFromPoint(ev.clientX, ev.clientY)
+        : [ ev.target ];
+    for ( const elem of elems ) {
+        if ( elem.matches(largeMediaElementSelector) && mediaNotLoaded(elem) ) {
+            toLoad.push(elem);
+        }
+    }
 
-    if ( mediaNotLoaded(elem) === false ) {
-        elem.removeAttribute(largeMediaElementAttribute);
+    if ( toLoad.length === 0 ) {
         stayOrLeave();
         return;
     }
 
-    loadImage(elem);
+    for ( const elem of toLoad ) {
+        loadImage(elem);
+    }
 
     ev.preventDefault();
     ev.stopPropagation();
@@ -210,7 +235,7 @@ document.addEventListener('error', onLoadError, true);
 
 /******************************************************************************/
 
-vAPI.shutdown.add(function() {
+vAPI.shutdown.add(( ) => {
     stayOrLeave(true);
 });
 
diff --git a/src/js/traffic.js b/src/js/traffic.js
index 481cd8916..e6adf3ffe 100644
--- a/src/js/traffic.js
+++ b/src/js/traffic.js
@@ -469,7 +469,7 @@ const onHeadersReceived = function(details) {
     if ( isRootDoc ) {
         const contentType = headerValueFromName('content-type', responseHeaders);
         if ( reMediaContentTypes.test(contentType) ) {
-            pageStore.allowLargeMediaElementsUntil = Date.now() + 86400000;
+            pageStore.allowLargeMediaElementsUntil = 0;
             return;
         }
     }