People from different places look different: point taken. But <i>everyone</i> looks different. I think what's offensive here is lumping everyone from a certain area of the world into one group, saying everyone from the east looks like one particular example, if that makes sense. Americans have a strong sense of individualism, and so generalizations that "all <i>these</i> people are like <i>this</i>" are sort of appalling, especially in a textbook. Particularly when these generalizations rely on race/ethnicity; it's sort of an unspoken us-vs.-them mentality.

Also, Americans have a volatile history of stereotyping people based on their looks, so we try really hard not to do that. It still happens, of course, but people make a conscious effort not to. Not all cultures have this history or think about this much either way, I don't think.

One more thought: The problem we have with calling someone by their race/ethnicity goes back to the individualism issue. If you call someone an Indian, you're defining him/her by ethnicity and all the implied stereotypes that go along with that. But if you say he's a guy from India, you're putting him (as a person) first, and then adding that he happens to be from India. Like I told my German students, you can use the stand-alone adjective when you're talking about food ("Let's go out for Chinese!") but not about a person.

*gets off soapbox* :)