Ticket #41948: 41948.patch

src/wp-admin/css/media.css

@@ -738 +738 @@
         box-sizing: border-box;
         padding: 16px;
         height: 100%;
+        background-position: 0px 0px, 10px 10px;
+    background-size: 20px 20px;
+    background-image: linear-gradient(45deg, #eee 25%, transparent 25%, transparent 75%, #eee 75%, #eee 100%),linear-gradient(45deg, #eee 25%, white 25%, white 75%, #eee 75%, #eee 100%);
 }
 
 .edit-attachment-frame .attachment-media-view .details-image {