A selfie that has been taken by a person who is not part of the picture. A regular photo, basically.
Person #1: Hey, can you make a selfie of me and my gang?
Person #2: A someoneelsie.
Person #1: What?
Person 2: You are not taking the picture yourself, so it's not a "selfie". It's a someoneelsie.
Person #1: Ugh, fine. Just take the picture, okay?
An absolutely foolproof way to keep minors from viewing content deemed "too mature" for them to watch.
Billy: "So I was trying to watch some videos for an M rated game, and I ran into an age gate, so I put in my real birthday. SOMEHOW it managed to figure out that I am 12. CURSE YOU AGE GATE!!!"
Bill: "Fucking age gate! *quick scroll* THERE! I was born on January 1, 1904. Fuck you age gate."