I love these two women (strangers) who are sitting on the train behind my friends.
There is always a choice to make when you realize you are inadvertently in someone else's photograph. You can say something/try to move out of the way/look down -- anything that somehow reduces/avoids your intrusion in the picture. OR... you can choose what these two women chose and say "You know what? Life is short. I am about to be in this total stranger's picture and I am going to own it. Hells ya! I am going to smile and look really cute and I'm gonna pose for that freakin' picture like I am Tyra fuckin' Banks. "