When first I came across René Magritte’s famous painting La trahison des images (The Treachery of Images), which says underneath a pipe in French “Ceci n’est pas une pipe”: “This is not a pipe,” I was quite confused. Of course it is a pipe. Just look at the painting!
I propose a simple test to check whether or not it actually is a pipe: put something in the pipe and smoke it. You can’t? Why not? If not a pipe, then what is it?