@Fillyfrog The reason you think you look so odd in photos is precisely because of the mirror thing.
You're used to identifying yourself as you see yourself in the mirror, which isn't what you truly look like, it's reversed. So when you look at yourself in a photo you're not seeing what you expect, and it gives you an uncanny valley sensation, that's something off.
Everyone else see's the non-reversed version of you all the time, so notices nothing different in a photo. (Weirdly, selfie cameras often flip the image for precisely this reason, so you think you look more like you. It does make you look off to anyone else who knows you).
There's also the fact its a still image. I think my DP is absolutely stunning. But she doesn't photograph well. She's still pretty, but suddenly she's not stunning. And I think the difference is the lack of movement, the little half smiles, eyebrow raises etc. Some people look better in a still image I think, but most look better in motion.