Wharton has a new essay this year that has given a lot of people trouble:
Tell us about a situation in which you were an outsider. What did you learn from the experience? (500 words)
I think the best way to approach this question is not to try to think of a situation that is profound, like a crazy culture shock situation or a time when you stood up to a murderous gang, etc. Use it as another chance to tell the admissions committee something you want them to know about you. For instance, I used a story that wasn't really monumental, but was a good segue into a discussion of my volunteer work and why I do it.
This question reminds me of a day back in high school. It was AP English, and we had our first Blue Book essay exam on The Odyssey. Our teacher wrote the question on the board: "Explain the role of dramatic humanism in the Odyssey". Well, "dramatic humanism" isn't something we'd ever discussed and no one know what it meant. Everyone in the class raised their hands, but all she would do was write one word on the board. COPE. So I did what I could. I made up a reasonable definition for the term and went with it. I got an A.
I think the admissions committee may be going for a similar angle with this question. It's a little oddball, not something any other school asks. Applicants aren't going to have a model to go by. Therefore, they are going to have to come up with something on their own, and maybe it will give the adcom a chance to really see how the applicant thinks. So I guess that's my advice for Round 2 applicants ... COPE!
Of course, maybe I'm wrong. Maybe they are just looking for insight into how you deal with uncomfortable situations or your attitudes about diversity. What do I know, I don't even know if I got in yet! ;)