A mirror is a flat mirror, which reflects light to your face, so what you see in the mirror is a relatively large image. This imaging method will not distort your image, nor will it make you look fatter or thinner.

In contrast, a camera lens is a lens that focuses light on a point to form an image. Different camera lenses will produce different effects. Some lenses may make you look fatter or thinner, depending on the focal length and optical characteristics of the lens.

In addition, the images taken by the camera may be affected by camera settings and lighting. If your camera is not set properly, such as using the wrong focal length or insufficient light, the photos you take may make you look fatter or thinner.

Therefore, if you want to take satisfactory photos, it is recommended to use appropriate camera settings and lenses, and pay attention to the differences between mirror images and actual images.