What is the role of the photo wall in China's ancient architecture?

Shadow wall, also known as shadow wall, the ancient name of Xiaowei, is a wall used to block the line of sight in China's traditional architecture. In olden times, people believed that their homes were constantly visited by ghosts. If there is a shadow wall, the ghosts will be scared away when they see their shadows. The shadow wall can also set the mood and increase the momentum of the residence.