Google is testing a longer search bar, so I guess you can enter in a longer query into the search box. Google is also testing it in a gray color and other variations.
I spotted this via SERP Alerts on X, who was tipped off by Sachin Patel on LinkedIn about this. But I can replicate it.
Here is the normal search bar – yesterday (hence the July 4th header):
Compare that to the longer search bar with a gray background filler:
They are also testing it without the gray color, there are more screenshots over here, if you care.
Google has told us that people are searching with many more words than ever before – so I guess this test makes sense.
Forum discussion at X.