This shows how the symmetry of the image from the chair to the shadow changes, it allows to get a different perspective of how the chair can look. It uses the angle of view from a high angle to expose the image to different light and create the shadow and change how the chair looks.
This is a good example of a high angle and a strong contrast of light and dark.
I find it a bit confusing to talk about the symmetry of this photo though. think of symmetry meaning that if you were to fold the image in half, the two sides would be very similar.