When lecturing on The Virtual Space Theory, a question that occasionally arises is the particular case of mirrors. Mirrors provide visual experiences via an object that does not physically contain any visual content. This fact is similar to the idea of virtuality as defined by The Virtual Space Theory. So what is the nature of what we see in mirrors? Is it or is it not virtual? This is indeed a confusing matter, and the following discussion about it, therefore, is suitable mostly for readers who are already somewhat familiar with The Virtual Space Theory.

Before entering this discussion, let’s begin by accurately addressing the topic using the terminology of The Virtual Space Theory. According to the Theory, the term ‘virtual’ describes visible objects that are located inside of virtual space. Virtual space, in turn, is defined as the visible space we can experience through pictorial objects such as paintings, photographs, and films, or what The Virtual Space Theory generally calls devices of illusion. The question before us, then, is whether or not mirrors can also be considered to be a type of ‘device of illusion’ through which virtual space can be experienced.
The Virtual Space Theory defines a device of illusion as a physical arrangement of physical matter which allows a person to experience through it something that is not physically there – the actual location of what is seen through it is within virtual space. However, a close comparison of this definition of devices of illusion to the nature of mirrors reveals two major differences:
Firstly, even though a mirror is indeed a physical object, it is not quite an ‘arrangement of matter’ in a similar way that paint on canvas or pixels on a screen are. The surface of the mirror is of course material, but the particular visual pattern that it presents is not part of the object itself – it is rather a redirection of light that originates elsewhere. That is the whole purpose of a mirror: to forward the visual pattern of light that reaches it with as little influence over that visual pattern as possible. As for a device of illusion, light either bounces off it (canvas, paper, etc.), emanates from it (LCD screens), or is projected onto it (projection screens). Yet in either case, the particular visual pattern of the device of illusion is not inherent to the ambient light that comes from its environment – it is inherent to the surface itself. This is due to the essence of a device of illusion: to present a crafted (essentially) flat pattern which can be visually interpreted as if it were showing objects in a space.
The second difference is that even though what is seen in a mirror (similar to devices of illusion) is indeed not located ‘physically there’ where the mirror image makes it seem to be, it is nevertheless located within the mirror’s physical environment. A possible exception is a distorting mirror – as seen in the example below – which makes the place and its contents seem altered in some way. Yet even then, the resulting image is still fundamentally dependent on the mirror’s physical location. A device of illusion, on the other hand, has no such limitations on the visual contents that can be seen through it. It can present any virtual place as long as the visual pattern can be arranged to make it seem as if that virtual place was located just behind the device of illusion’s surface.
The close relation of mirrors to pictorial illusions has made them a recurring motif in the works of many artists, as seen in this example by M.C. Escher. According to The Virtual Space Theory, since it is a pictorial image, of course everything that is seen in it is located inside of virtual space. Yet in this context, our interest is rather in understanding the scene which it presents to us, and so we should approach it as a suggested physical experiment. Therefore, if you were to hold such a spherical mirror in your own hand, we could surely say that the mirror and your hand are physical objects, but what about the person reflected in the mirror and the space behind them?
According to the above analysis, then, the visual contents seen in a mirror are not in virtual space and they are not virtual. What mirrors show are simply physical objects, which in addition to their direct visibility, also have a visual reflection in a mirror. The actual location of these objects, however, is nearby (or not so near) in physical space. Such a visual phenomenon is indeed fascinating, yet it is very different from that of pictorial illusions as defined by The Virtual Space Theory. The term ‘virtual’, therefore, despite its current popular use, is both unrelated to the case of mirrors and unnecessary for its understanding.
It is an age-old phenomenon, and it has an equally old term for describing it:
A reflection.
