In chapter 3, how is Nick different than the other people at Gatsby's party?

In The Great Gatsby, at Gatsby's party in chapter three, Nick is an outsider.  He is from the Midwest not from the East, and he is not from the same social circles or economic class as the other guests.

He is an outsider throughout the novel.  He watches Gatsby's story develop from the outside, without direct involvement.  He is present, and performs little tasks like inviting Daisy to tea so Gatsby can be there and meet her after not seeing her for five years, but he is still an outsider. 

This is his role as narrator.  If he were "one of them," his narration of necessity would be different.  But he is not.  Not at the party and not at anytime in the novel.   

This sets up the contrast between Midwestern values and Eastern, the contrast between the myth of the American Dream and the reality, and the value judgments about easterners like Tom.