By pointedly choosing to portray subjects that were two-dimensional in their own right, he was pursuing the path set a decade earlier when Jasper Johns first painted an American flag, ingeniously showing that the vaunted flatness of Abstract Expressionism could paradoxically be consistent withrealism in certain circumstances.
While we need both aspects of our emotional mind -- rainy and sunny -- to live life to the full, there is abundant evidence that an optimistic take on the world, especially when linked withrealism, is associated with better health, more success and a deeper sense of well-being.