a selfie taken for the sole purpose of proving to her crazy, controlling significant other that she is having a boring outing and not cheating on her crazy, controlling significant other
Mendy asked to take a "proof selfie" after the boring-ass lunch, just so she could send it to Joe, so he wouldn't homicide her when she got home
A selfie taken solely to establish one's whereabouts so as to avoid being homicide by one's insanely jealous significant other.
Before they left the restaurant, Mendy made her disgusted friends pose for a pathetic proof selfie.