Well i used to wonder the same before i started studying photography, i can tell you this could be for 2 main reasons..
1. you are taking the pictures from the wrong angle, example: if you take a picture of your face from a down angle, you are going to look with a double chin, if you take it from upper angle you are going to look skinnier.
you also should take a picture of you in every single profile until you find the best for you.
2. For self pictures put your camera as far as possible from your face and if you wanna take a closeup ALWAYS use your ZOOM, but NEVER put your camera too close because that just gonna make your face look weird. example: a bigger nose, a bigger forehead, ugly lips.
I hope this helped you!!
(English is not my first language so sorry if a messed up!)
· 1 decade ago