WordPress 6.7 added the ability to delay loading images with sizes="auto". This feature, recently added to the HTML specification, allows browsers to use an image's rendered layout width, srcset, when selecting a source from a list, since delayed-loaded images don't load until after the layout is known. Background The responsive image attribute, srcset, was added in WordPress 4.4sizes. To quote a developer note from that time: To help browsers from the list of source sets...