Why isn't there an img-tag in the default example? Why are you promoting bad practice by not having images in img-tags? You solved one problem but created a much bigger problem. Bots, screen readers and non-javascript client should see an image, not a div with some attributes.
They're welcome to target whichever type of users they want to - it's 2014, most average internet users have javascript enabled. Besides, you can add a title/aria-* attribute for bots and screenreaders (perhaps not semantically correct but gets the job done).