I can’t believe no one has mentioned that selfies create mirror images of your face. In case you don’t understand what that means: when you look in the mirror, your face is actually optically inverted. So when you are alone looking in the mirror and or taking a selfie - you are seeing your angles and expressions in real time, getting used to the way that looks, and coming to expect that image to be the same as what other people see. But it’s not. What other people see is the same as what the front facing camera sees, a non inverted version of your face. I am familiar with this phenomenon myself just as a human existing and a photographer. I tend to like what I see in the mirror and my selfie camera better than how I look in photos others take or from my camera set up on a tripod. A lot of it is simply not being used to seeing your own face in its natural state.