Because it can produce a few notes, though they are VERY flat; and it is nevar put with the wrong end in front.
That is the "official" answer given by Lewis Carroll himself in the introduction to a late edition of Alice's Adventures in Wonderland. Although, as mentioned below, originally it was intended to be just a bit of nonsense with no answer.
there is no answer to the question. it didn't intend to have a answer in the first place
there are many creative answers that you can come up for it but it origialy had no answer to begin with.