Google is testing another search result snippet interface change, this one is when you hover your mouse over the snippet, it adds a shadow effect to the snippet.
This was spotted by Brodie Clark who shared a video of it on X (also here - here it is):
Four years ago, we saw Google testing shadows on search results but it wasn't based on hovering your mouse over the snippet.
Bing also had a weird hover shadow experiment earlier this year.
Forum discussion at X.