Horizontal planes at different levels combined with vertical planes "look" visually interesting.
It divides the flat space into smaller zones or clusters; simultaneously they create headroom below it. Domes, pyramids and cones or any other solid form give rise to different kind of volumes and empty spaces below it. Architecturally these solids are interesting externally whereas voids are "useful" internally. A visual designer needs to be Trained to simultaneously process the images of the external solid shape and its corresponding internal empty space.

Retrospective analysis

Internal spaces and external spaces can further be coloured and applied with linear graphics. Various textures applied externally can also make the positive form more solid.