Hand gestures and their meanings vary
Those peace signs Asian tourists (and I admit, I as well) love doing? Totally cool. But flip that around, with the back of your hand facing the person, and you've essentially turned it into a middle-finger salute in places like the UK, Ireland, and Australia.
It's not just the hammy peace sign. A number of other hand gestures, innocuous in some Western countries, are hideously offensive in others. Pointing seems pretty natural and harmless, until you get to China, where it's a gesture meant for dogs. But then, Chinese people would point with their middle finger, not realizing what that means. And while we're still talking about miscommunicating in China, sticking your pinky out means that you are not happy with something (like a thumbs-down), though it's not that common.