What exactly does it mean to look "British"?

It would mean something different for everyone. My Dad and I will say that someone looks like a pom if they have bad teeth and pasty skin. Obviously not all British people have bad teeth and pasty skin...I dated a British guy who was built like a Ken doll. But the majority that you see on reality TV shows or backpacking have really really bad teeth. I heard that it's because there's not as much awareness in Britain about dental hygeine, and that it's also more expensive. A friend of mine is British and he looks like he's got about twenty extra teeth in his top jaw alone.