While thinking of which is more accurate mirror or camera, it is best to know that selfies can alter the look of facial features. Front-facing cameras could have wide lenses and take pictures from a closer distance to the face, thus altering proportions, according to Visuals Clipping. The preview might also be mirrored based on the phone's setting. A reflection and a photo of a person will therefore show the same person from different angles, from different distances and at different times, so there are some visible differences that are perfectly normal.