What is Sienna Miller so pissed off about?

We'll admit it. We have very little interest in why Sienna Miller is at this fashhhsion bash and who that man beside her is (he's actually retail entrepreneur Harold Tillman, in case you wanted to know), but we do find this picture rather amusing.

First of all, it's clear that Sienna's smile is about as real as Jodie Marsh's boobs - and she looks as if she needs a pee really desperately! He is clearly thrilled to be standing next to Sienna, but probably more because she makes him look more tanned than anything else. Then again, he'd make a freshly Ronsealed garden fence look pasty by comparison. Can you think of a better caption than us? Go on! We challenge you!