"Ceci n'est pas une pipe." is the realistic representation of a pipe and not the pipe itself. Simple as that.
There are some paintings and artworks that are part of the western cultural heritage and are used in propaganda, graphic design, clothes stamps... they are everywhere.
I decided to post some of them so that those who don't know them can identify that the T-shirt they wearing is inspired by one of this famous art pieces. Art is not being teached anywhere and only those who like it very much have access to this world.
I hope it helps some people knowing these renowned pieces.