Unity and repetition. A great example of Unity; with the repetition of the arc structure and reflection, place this image in a way that brings them all together. The spacing within the shadow on the wall also creates the sense of great proximity and mood.
LIGHT: This is a photography of a hallway in a cathedral. There is very white, visual light shining through the windows which creates shadows on the floor. The design is very clear and simple because there are no colors or any disaccords.