Have you noticed that when you look at your selfies, your face looks a bit, well, weird? This is because what you see on the screen when you take a selfie is the mirror image of what you actually look like — that is to say, it's what you see when you look in the mirror. But, by default, your phone will produce a non-mirrored version of you in your final photo.
Nobody's face is exactly symmetrical. You might part your hair on one side, or have a mole on one side of your face, or have a slightly lopsided smile. We're so used to seeing the mirror-image version of ourselves every time we brush our teeth that our brains think that's the correct version of our appearance. There's even a scientific term for this: Mere Exposure. People prefer the look of things they're more familiar with. This is why we often think our faces look "wrong" in photos of ourselves.
