iTunes "Find Artwork"

Not that it is a major issue, but I had imported a hard copy of "Dark Side Of The Moon". I then went to find the artwork and some altered version of the cover came up. Instead of the light through the prism, it was light through a silhouetted head. it is not like DSOTM is some obscure rarely seen artwork, but one of the most recognizable covers known. like I said, it is not a big issue. I am just curious on how this artwork is obtained.