Google seems to have launched image thumbnails in the sitelinks of the mobile search result snippets. If you search for [bear] on Google mobile search and look at the Sitelinks for the Wikipeida snippet, you will see these images in the Sitelinks carousel.
I didn’t see the feature working yesterday, I did see it working this morning. Here is a screen shot showing the sitelinks with thumbnails (I was able to take this screen shot myself):
Here is what it looked like yesterday for me:
I tried to replicate it for cat, lion, rat, etc – so far no luck yet. But I do suspect it comes up for a lot of searches on mobile.
This does look like a similar effort to the image thumbnails for image search refinements we covered just before.
Forum discussion at Twitter.
Zoomd Custom Site Search