Left and right swap
The image in a plane mirror is identical to the object, except that it is turned round left to right. This is lateral inversion.
Figure to be added
The word AMBULANCE is written backwards on the front of an ambulance (ƎƆNA⅃UBMA). When the ambulance is behind another vehicle, its driver sees the word in the rear-view mirror turned the right way round, and reads AMBULANCE.
Swapped left to right, never upside down
A plane mirror's image is upright, the same size, as far behind the mirror as the object is in front — and laterally inverted.