Question

what is lateral inversion

Answer 1

Lateral inversion" means the apparent reversal of the mirror image's left and right when compared with the object. "Lateral" just means "sideways".

Answer 2

A lateral inversion is the real or apparent reversal of left and right. For example, the letter b when laterally inverted becomes the letter d (more or less). It is well-known that a plane mirror causes the apparent lateral inversion of objects.