* An NFT is just a pointer - could contain a URL, or just a number used by its smart contract.

* The artwork is just pointed to, it's not on the blockchain.

* The URL may or may not exist for any given length of time either. (Even some NFTs that tried to point to IPFS, actually pointed to an IPFS redirector.)

* No other rights - copyright, moral rights, reuse rights, etc - are conveyed without an explicit contractual transfer. Even the Christie's deal says, once you dig through the 33-page sales agreement, that you are just buying the token itself, and not the image pointed to.

Also, you have zero guarantee that the artist had anything to do with that particular NFT - and there's a lot of NFT grifters "minting" other people's art.