M. C. Escher, one of the 20th century leading artists, is best-known with his impressive optical illusions. Especially in “Impossible constructions” collection, he did excellent works in playing various visual tricks on those artworks that profoundly confuse the observers at the first sign. The piece of art “ Relativy” depicts an unrealistic interior space with the stairs that never go the same way, the floors, doors and balconies are put on every sides of the rooms in this view. There are also a number of people climbing up and down the stairs and assign “up” or “down” direction in a complicated and strange way, thus completely confuse our visual analysis. However, if the people in motion is supposed to be invisible in the picture, the structure, especially the stairs system seems to be visually possible and at least overall perspective cannot look occur, even though the positions of other furniture pieces may not make logical sense. Therefore, it is effortless for grouping structural elements which are of the same shade and well-connected and well-defined in mass and form. Otherwise, when the number of people moving is involved in the perspective, it can be seen that their shade visually matching with the construction as well as the visual tricks occur to make the picture look ambiguous itself. This is because that three out of four main stairs seem to allow people to climb on both top and bottom, reach and stand on every interior sides of the building, and most of their positions may also be impossible because they defy the force of gravity. In this case, the combination of proximity and shade grouping of the construction and the people in motion play a trick on our eyes if we look at overall picture including the motion, but neither attention nor awareness contribute to the grouping process. This symmetry processing can also be influenced by cueing, task requirements and voluntary control. First, we are noted that there will be some perspective tricks as we are observing the picture and we are able to guess what will lead to our corresponding visual analysis right away. Second, task requirements help us to filter data and obtain necessary information efficiently based on a clear benchmark . Referring back to the picture “ Relativy”, to determine whether symmetry-cognition is actually linked, the involvement of attention should be confirmed .Third, voluntary control whether we perceive this symmetry by grouping by motion or by grouping by symmetry. In this case, the percept we may see is mainly by grouping by symmetry. We may notice that the interior structure of the building especially the stairs system has some kind of rotational symmetry axis that causes this grouping process.