Google seems to be showing a new radio button selection filter for the image search drop down filters. As you can see from the screenshot below, when you click on a filter option, it shows the option but also a circle to select it.
The interesting part is that you cannot select multiple filter options in the same filter type at the same time. You can only select one. I also do not see the radio select boxes in the main mobile search results, I only see them in the image search results.
Saad AK notified me of this on Twitter and shared some more examples, but please note, I can replicate this:
Here are more screenshots (for another query).
Query: makeup
Sending to: @rustybrick SIR. pic.twitter.com/CFOS4xWRJ2— Saad AK (@SaadAlikhan1994) March 23, 2021
Forum discussion at Twitter.