unity because the cough and walls have the same idea of outline square or shape with white. the walls and couch have white rectangles on them. they are similar. unity is created by choosing items with similar characteristics. results in harmonious design
Some rooms need to be studied: notice the recurring pattern of circles in the ceiling, carpet and fireplace; the use of brass accents; the variety of dentil moldings in the ceiling; the monochromatic color scheme...all put together for a very interesting composition.