https://commons.wikimedia.org/wiki/Commons:Derivative_works has some commentary on how this works you might find interesting
I get that copyright is a bit of a minefield, and there's some clear cases that should not be allowed, e.g. taking photos of a painting and selling them
That said, I still get the impression that the laws are way too broad and there would be little harm if we reduced their scope. I think we should be allowed to post pictures of Pokemon toys to Wikipedia for example.
I'm willing to listen to other points of view if people want to share though
Not to mention that wikimedia commons, which tries to be a globally reusable repository ignores fair use (which is context dependent), which covers a lot of the cases where copyright law is just being reduculous.