Just showing how keen observer you can be. This image may look like a normal figure but scrutinizing every detail would definitely tells you that it is not. Your mind has been deceived by this optical illusion.
An optical illusion is always characterized by visually perceived images that, at least in common sense terms, are deceptive or misleading. Therefore, the information gathered by the eye is processed by the brain to give, on the face of it, a percept that does not tally with a physical measurement of the stimulus source. A conventional assumption is that there are physiological illusions that occur naturally and cognitive illusions that can be demonstrated by specific visual tricks that say something more basic about how human perceptual systems work. The human brain constructs a world inside our head based on what it samples from the surrounding environment. However sometimes it tries to organize this information it thinks best while other times it fills in the gaps. This way in which our brain works is the basis of an illusion.
If you see some artworks that visually seems like the real image but actually differs from the real one like it is distorted, it is an optical illusion.
