If you put togheter three of these mirrors, in the zone
where they touch you can look at an even more extraordinary image.In fact you have in each sphere a reduced size mirror image of the other two spheres, which of course contain a reduced size images of the other two sphere, which ...
This is an example of fractal. You can thing of a fractal image as a tessellation where instead of tiling the plane with the patterns of the same size , you use patterns of decreasing size.
The simplest way to tessellate plane with this different size patterns is a spiral.
There are many examples of fractals in Nature: trees, mountains, clouds, etc... But fractals have become famous after the advent of cheap graphics computers, since they can easily be drawn with simple algorithms. The most famous computer generated fractal is the Mandelbrot set. It is also a immensely complex tiling of the plane, but as you zoom in, new copies of the bug shaped set appear.