It seems like if you’re posing for a portrait, there are some common-sense rules. Look at the camera lens. Don’t hold a phone in front of your face. But somehow when people use a mirror to take their own portrait, these basic rules are forgotten. I documented 100 consecutive mirror selfies on popular dating apps (Bumble, Coffee Meets Bagel, Hinge, The League, and Tinder), noting whether they failed and how. The main conclusion: The vast majority failed.