Google loves their refinement bubbles so much that they are also testing it on the image search box in web search. They have it for featured snippets, videos and for image search and many other cases and now they are testing it in the image search box directly in web search.
I believe Dan Shure was the first to spot this and posted on Twitter, then Brodie Clark posted on Twitter and I also got an email from Frank. Thanks for all your notifications.
Here is what it looks like with the test of refinement bubbles:
Here is what it looks like without it:
Here are more screen shots:
Forum discussion at Twitter.