There must be a better explanation for this strange behaviour!

[pazu]

Is it a cultural difference? Or just a joke? Or was it another kind of behavioral arts combined with a joke to show how hilarious it could be when you encountered a cultural shock?

For those laowai who didn't have a clue as to how to use the"beer glass" in China, it is simply a urinal.

[zhwj]

a) It's a spittoon, isn't it? Chamber pots usually have a handle, and often a lid. Here's one of those:

B) It's just people having a little fun. They bought lots of identical pots (new, I'm sure, not from someone who'd been using them), and they took the pictures themselves, so I'd guess they knew exactly what they're doing. Show the pictures to someone, and they'll say "WTF? You don't drink beer out of that!" Precisely the reaction they want.

See here if you want more shots of the same day.