It is supposed to illustrate the two sides of cigarette smoking: the pink and the blue represent the act of smoking as being something "cool" and stylish and it is supposed to remind the viewer of the old days when smoking was seen as something natural, permitted and even encouraged. The black part that is behind the pink and blue ones and which actually dominates the piece through its size and aggressive shape, comes as a grim reminder that smoking is actually a bad thing, that it's all about black lungs, clogged arteries and eventually a slow and painful death, in a nutshell: smoking kills.