You could call this a surreal geometric painting as it has rectangular shapes and a sense of the unreal, however it is also minimal. Only a few shapes are there, the smallest amount to create the feeling desired. Colour is important here, not too many and not too bright, but soft muted tones - nuances to please the eye but also add uncertainty as to what one is viewing. Watercolour works well for this type of painting, it is in summary a minimal geometric piece to create a pseudo reality - surrealism.