We do agree that at the first look, you might feel that there is nothing wrong with this figure. However, if you take a closer look, you will recognize the problem. See the bridge joining and you will agree to the fact that no matter how normal it appears, it certainly cannot exist in the real world. We call such illusions as paradox illusions. The plank that is connecting both ends is simply not feasible in reality. Look closely and you will find other contradicting things as well.