I'm not surprised, mis-reading of foreigners' body language is very easy and difficult to pinpoint for many people because generally very few analyze it consciously.

And we all tend to have a few specific images related to other countries, and just those.
I was very surprised when whatching a Spanish TV program featuring what I thought was Irish folk music (including instuments that looked like uillean pipes to me and landscapes with white straw-hatched cottages) to discover that they were actually showing Asturian landscapes and featuring Asturian folk-music, and I lost count of the people who tell me 'you're Italian, really? I thought you were ...' (insert Northern or Central European nationality) because of my light hair and eyes.

I wonder how people would react to a story featuring a Chinese-national Eluosi http://en.wikipedia.org/wiki/Eluosizu as main character...