The folks who track the structured data results spotted a new AMP carousel in mobile for hotel listings. Brad Brewer posted in a Google+ thread that Google is now showing AMP carousels for hotel listings.
Here is an example for a search on [10 best Hotels in Clearwater Beach]:
I believe this is a new AMP carousel and probably related to new structured data around AMP and local listings. Brad said he is now going to test by adding more markup to some listings to see if he can replicate.
Forum discussion at Google+.