Why do you feel wide when you are close to the mirror?

The mirror is flat, but. The face is round. As soon as the face is close to the mirror, the front part looks big (near big and far small) and the back part looks small. This caused the face to be disproportionate. It looks a little wide.

In fact, from a distance, it is also distorted. Just because it's far away, it doesn't look so obvious. The proportion is not that big.