Not really. It's not clear to me that any IP in the photo was sold. The OP says "And as is the case with many NFT sales, the Roths also retain the copyright to

Not really. It's not clear to me that any IP in the photo was sold. The OP says "And as is the case with many NFT sales, the Roths also retain the copyright to the image and will make 10 percent off any future sales of the NFT." If you want to buy the copyright to something (or a license to it), you don't need an NFT. There was already a market price put on IP, you don't need NFTs for that. I have no idea what NFTs are for.