Since light from the object appears to diverge from this location, a person who sights along a line at this location will perceive a replica or reproduction of the actual object.
In the case of plane mirrors, the image is said to be a virtual image.
"Virtual images" are images which are formed in locations where light does not actually reach. Light does not actually pass through the location on the other side of the mirror; it only appears to an observer as though the light were coming from this position. Whenever a mirror (whether a plane mirror or otherwise) creates an image which is virtual, it will be located behind the mirror where light does not really pass.
Besides the fact that plane mirror images are "virtual", there are several other characteristics which are worth noting.
The second characteristic has to do with the orientation of the image.
If you view an image of yourself in a plane mirror, you will quickly notice that there is a left-right reversal of the image. That is, if you raise your left hand, you will notice that the image raises its right hand. This is termed "left-right reversal". This characteristic becomes even more obvious if you wear a shirt with lettering.
While there is a left-right reversal of the orientation of the image,
there is no top-bottom vertical reversal. If you stand on your feet in
front of a plane mirror, the image does not stand on its head. Similarly,
the ceiling does not become the floor. The image is said to be "upright",
as opposed to inverted.
A third characteristic of plane mirror images pertains to the relationship between the object's distance to the mirror and the image's distance to the mirror. For plane mirrors, the object distance (is equal to the image distance.
That is the image is the same distance behind the mirror as the object is in front of the mirror. If you stand a distance of 2 meters from a plane mirror, you must look at a location 2 meters behind the mirror in order to view your image.
A fourth and final characteristic of plane mirror images is that the dimensions of the image are the same as the dimensions of the object.
If a 1.6-meter tall person stands in front of a mirror, he/she will see an image which is 1.6-meters tall. If a penny with a diameter of 18-mm is placed in front of a plane mirror, the image of the penny has a diameter of 18 mm.
The ratio of the image dimensions to the object dimensions is termed the "magnification". Plane mirrors produce images which have a magnification of 1.
In conclusion, plane mirrors produce images with a number of distinguishable characteristics. Images formed by plane mirrors are virtual, upright, left-right reversed, the same distance from the mirror as the object's distance, and the same size as the object.