It's a tribute to Elvis. The words aren't about Elvis, per se, but they are like songs he sang and unlike other songs that Queen did. The music style and the singing style aren't like Queen, they're like Queen trying to be Elvis - as a tribute, not to rip him off. It works, for the most part. It wouldn't be as genuine if they wrote a song describing Elvis, because they only knew the public Elvis Presley, not the personal Aaron Presley.