It was forgivable for @benthompson to write this in February, but he shouldn't be repeating it in April. It's just not true.

An NFT is a token that points to a file on the internet. Often (but not always) that file lives on IPFS. But wherever it lives, the file does not point to the token. The pointing only goes one way.

For any given file on the internet, it is unknowable now many NFTs might be pointing to it. So putting aside all the questions about what "ownership" actually means in this context (spoiler: almost nothing), it's not possible to know who owns a file just by looking at the file.

Any given token can be unique. But anybody can create an NFT that points to any file. Even a Taylor Swift song. So while the blockchain can tell you who owns any given NFT, it tells you nothing about who owns any given piece of digital art.