When you look in the mirror, you look like a mirror, that is to say, most of what you see in your life is different from what others see you, mainly because our faces are usually somewhat asymmetrical, or not so completely symmetrical. What you see is a mirror image, others see a normal mirror image. The picture taken by the camera is normal, and you are the same as everyone sees you, so it can also explain why you are the only one who says you look weird, and others say it is normal after taking pictures.

As for why it doesn't look good, it's because we are used to our own mirror image. When there are some subtle changes, such as seeing a normal image, we will come to an embarrassing conclusion, because these challenges our usual cognition, so that we feel that we don't look good in the photo.