People Take Pictures of Each Other

Tonight's class we took pictures of each other, using lighting diagrams and ideas that we came up with as an assignment. It was weird, because the pictures didn't look anything at all like me. I've shot a couple of self-portraits and in countless family and travel pictures, I've always looked like myself. Even my driver's license looks like me. But for some reason, the pictures one of my classmates took of me looked like somebody else. Is this strange of me to think this? Or is it something that happens all the time and nobody ever says anything?