Can you just ask the person whose autograph you want to give you one of their pictures/headshots? I think that would be way easier, especially since they probably have tons of them anyway.

If you live in United States send a properly stamped and self addressed envelope (minimum size 8.5" x 4") with your request letter and a photo.

By a photo, do you mean a photo of the person whose autograph you want?? Yeah, I know, this is a really stupid question, LOL