N + 치고는 shows that the person is an exception to generally recognised rule, and that the speaker is surprised at this. It roughly translates as “you’re pretty… for an N”, and is often followed by 은 편이다 (tends to be…):
외국인치고는 한국말 잘 하네요.
For a foreigner you speak Korean well.
눙구 선수치고는 그는 키가 작은 편이에요.
For a basketball player he’s a bit on the short side.
바레인에 있는 식당치고는 음식 값이 싼 것 같아요.
For a restaurant in Bahrain, the prices seem cheap.
초등학생치고는 음식을 많이 먹네요.
For a primary school student he eats a lot.
자기 나라 밖에 살아 본 적이 없는 사람치고는 한국 문화에 너무 잘 적응하는 것 같아요.
For someone who has never lived outside his own country before, he seems to be adjusting to Korean culture very well.