Google is now showing image thumbnails in the mobile search results for select queries.
The queries seem to be product-based queries where the user might find an image of the product useful.
Google was actually testing this back in August 2016 and also earlier in December 2014, and it now seems to be showing for all mobile searchers.
I was personally able to replicate it and had them come up for me for searches from door locks to wine glasses to searches on types of cars or color of cars.
Here are some screen shots of how they look in the mobile search results.
We asked Google for a comment about this yesterday but did not hear back by the time we published this story.