I look different in pictures, mirrors and pictures taken from someone else?

Basically i look in the mirror and i think i'm pretty, i've been told by people i'm pretty ot beautiful. I know that my nose is slightly turned a bit more to the right which means photos on my right side enhance it and thats why i always take pictures from the left side. Also one of my eyebrows is slightly just slightly lower. Now when i look in the mirror i'm happy with the way i look. The front camera on my iphone also reverses the picture to what it should look like and i look fine in that aswell. The normal camera on the back of the iphone is what i have a love hate relationship with. Everyone tells me i'm photogenic which i find hard to believe. When i take pictures myself inside or outside with the back camera my face looks fatter and wider, it makes my eyes look droppier. But when someone else takes family photos or pictures with same camera i look pretty! (Not sounding vain) and i look fine in every photo! Why is this? It makes me feel down about myself. I think if you want to see how people see you, you should reflect your reflection on a mirror onto another mirror. And thats what you should look like? Am i right?

Holding any camera at arm's length or closer (like stupid teens do with their phones) causes heavy distortion on the photo.

Of course you look different in photos taken from different positions. Taking a photo from arm's length using a wide angle lens is going to create a lot of distortion.