The middle image is an upright image. The magnification of the middle image is -1. When sighting at the middle image, light will reflect twice prior to reaching one's eye. Two plane mirrors are attached to form a dual mirror system with an adjustable angle. Virtual images are always located behind the mirror.
Virtual images can be either upright or inverted.
Virtual images can be magnified in size, reduced in size or the same size as the object. Virtual images can be formed by concave, convex and plane mirrors. Virtual images result when the reflected light rays diverge. Virtual images can be projected onto a sheet of paper. Real images are always located behind the mirror.