---- How To Tell Google Which Image Is The Main Image?
freejung - 3:43 pm on Nov 7, 2011 (gmt 0)
In principle schema.org ought to solve this problem, I don't know whether that works in practice yet.
That's true, however it also ought to be possible to use the same clever libraries to implement the same functionality in a way that's clear to search engines.
In this example, why not put all of the images in img tags somewhere on the page, then use JS to set them to display:none? That way they're already in the browser cache when you use JS to display them on click, and they'll be indexed as well.