Google is testing another version of the image search preview window, this one is an overlay that hovers over the image search results after you click on the image. Earlier this week, we saw Google test place this image search preview on the right side of the search results.
Here is a screen shot from Matt Docherty on Twitter of this design, you can click on it to enlarge it:
Here is what the test from earlier this week looked like:
Here is what I see, and what you probably see:
It is unclear if Google will launch any of these but Google is almost always testing user interfaces.
Forum discussion at Twitter.