Should see two green squares if object-tag data=dataURL MIME types are case-insensitive.<br/>

<object width="200" height="200" data="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAIAAACQd1PeAAAADElEQVQIHWNg+M8AAAICAQDpLOrTAAAAAElFTkSuQmCC"></object>
<object width="200" height="200" data="data:iMaGe/PNG;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAIAAACQd1PeAAAADElEQVQIHWNg+M8AAAICAQDpLOrTAAAAAElFTkSuQmCC"></object>