Ahhh... 'Mouse Trap' a favorite Abstra-Cat using posterization. Simplification of the form using only three values - dark, mid, and light. The Japanese use a term called "notan" as a way to express "light-dark" as an element of design. Positive space and negative space are divided into separate components.
Below are two examples of this design element. The first by George Seurat and the second painting by me. I really love the abstraction of positive and negative shapes. I think George and I nailed it!