I'm no expert on this, but from what I've seen, most NFTs are as simple as an incremented ID field mapped to your wallet address and stored in a smart contract.

I'm no expert on this, but from what I've seen, most NFTs are as simple as an incremented ID field mapped to your wallet address and stored in a smart contract. You (usually) don't buy any rights to the image in the first place, and what the ID represents is not guaranteed to persist by any part of the agreement. So, if the author kept the copyright to the images I suppose they could sell it and then prevent the NFT owner from displaying the image itself. Seems like a fast way to burn your reputation as an artist or developer. I would guess that most popular projects license their images under creative commons, and encourage people to copy and share them, so that the original authors can't just overwrite them, since there would be lots of backups and a social consensus as to what each ID represents.