Google is testing a new image pack design that shows four images instead of three images with a more images button. This may not be a new change, it might be query dependent but it seems newish to me.
I mean, the image box in Google Search can change and show more or less images based on your query or Google's understanding of your query.
But Sachu Patel posted two screenshots of the image pack showing three versus four images, plus one with a more image button to see more - he posted this on X. Here they are side by side:
Again, this may be new or not?
Forum discussion at X.
Note: This was pre-written and scheduled to be posted today, I am currently offline for Sukkot.