"The famous pipe. How people reproached me for it! And yet, could you stuff my pipe? No, it's just a representation, is it not? So if I had written on my picture 'This is a pipe', I'd have been lying!"
His statement is taken to mean that the painting itself is not a pipe. The painting is merely an image of a pipe. Hence, the description, "this is not a pipe." The theme of pipes with the text "Ceci n'est pas une pipe" is extended in his 1966 painting, Les Deux Mystères.