If the Louvre decided to sell an NFT of the Mona Lisa, nothing prevents them from generating another NFT (or a few thousand) of it as well. Same thing for an NF

If the Louvre decided to sell an NFT of the Mona Lisa, nothing prevents them from generating another NFT (or a few thousand) of it as well. Same thing for an NFT pointing to an image at some URL and containing a hash of that image, it doesn't actually generate ownership of that art in any legally meaningful (or enforceable) way. Digital ownership only works for things that 100% stay in the digital realm, and even then it's not a guarantee.