Why were old pipes often held upside down?

https://preview.redd.it/2uib9mpfk4oe1.png?width=240&format=png&auto=webp&s=53746aedf2af19b52d8fb8b75f244c4b11c4106c

I've seen pictures besides this one of people with an old pipe in their mouth, held upside down. Why was this?