Yes, one of my favorite jankinesses is that iTunes would put a timestamp in the jpeg header of the embedded artwork for every m4a file, ensuring that a hash of

Yes, one of my favorite jankinesses is that iTunes would put a timestamp in the jpeg header of the embedded artwork for every m4a file, ensuring that a hash of the artwork (for a library system that tried to minimize duplicate artwork) would always be unique. So you’d have a visually-identical but duplicate artwork file for every song on the album.