This is a cute mobile search feature, where Google is showing you a carousel of GIFs that you can click on to share with your friends. It is query dependent, and will match relevant GIFs to your query.
Here is what it looks like:
Saad AK spotted this and posted about it on Twitter and I can replicate it.
When you click on “Share” the native iOS or Android sharing bar comes up so you can share it via email, text messages, social media or wherever.
This does not seem to show up on desktop.
Forum discussion at Twitter.