I've been to multiple museums in Japan (which is somewhat relevant because Nintendo is Japanese) that either flat out ban all photography (e.g. Ghibli Museum, Aomori Museum of Modern Art) or have some exhibits that you're not allowed to take pictures of (e.g. Tokyo National Museum). One exhibit I wanted to take a picture of had a "no photography" sticker on it, but it was on the opposite side from where I approached so I didn't see it, causing staff to run up to me when I pulled out my phone to point out the sign.

I've also heard from other tourists that "no photos" seems to be rather common there.

Btw, I'm not at all saying that they're justified at all, just saying that there are indeed places that forbid photos for copyright reasons. In my opinion, no photo would ever match seeing the exhibits in person so it is entirely pointless to ban them. Even professional, official scans of pieces don't come close.