Not bad! Unlike the hundred "link every keyword on a page to a tenuously related product" scripts out there, this actually adds value to the page, highlighting and identifying items in the photo on hover.
Disable your adblocker.
I'm having the same issue. My add blocker is turned off and I don't see anything when hovering over the images on that blog post.
Can confirm. Does not work on Chrome.
Works fine on chrome/OSX for me. Make sure you went to the right page (hangover things, not the girl doing yoga)
Really, really great idea. This would be an absolutely fantastic addition to something like instagram.