It's a neat way of controlling and exchanging numbers among other numbers. The correspondence to a given number to an image or anything else is entirely a matter of convention, however.
Crypto nerds think NFTs will solve everything including music distribution. I just don't get how making the process even harder will help musicians. People are to buggered to visit music stores or even download music. It's so cheap and easy now, why the hell do they think people would buy a song on an NFT? How do you even listen to an NFT?