Just checked in store just now and all the iPad minis on display had it. I do wonder if some people’s eyes are more able to see it than others. Basically when you scroll in portrait, especially with text, the lines of text will appear to tilt diagonally to one side. I didn’t have to go looking for this, it was immediately apparent. Interestingly, I also noticed it on the iPad Pro’s in store, only in portrait mode, and not as dramatic as on the Mini.
I’ve been using iPads since the original iPad came out and never seen this behaviour before to this degree. Possibly related to iPadOS 15? Don’t know. 🤔