You got ready this morning and you looked FAB! Then an hour later you snap a selfie with a friend and... WOAH! Who is that? WHAT is that? You think, "I look awful!" 10 minutes later you take a bathroom break and you catch your reflection and you look fine. Great even. So you come to one conclusion... your camera is a jerk!
But your camera is actually perfectly nice. There is just a lot at play here that makes you look "weird."