Here's the question that I copied from Scooby's post. It's actually the same question that they ask every year, they just decided not to ask the other essay questions this year.
8. The Committee on Admissions regards the diversity of an entering class as an important factor in serving the educational mission of the school. Although answering this question is optional, the Committee on Admissions strongly encourages you to share unique, personally important, and/or challenging factors in your background, such as the quality of your early educational environment, socioeconomic status, culture, race, ethnicity, or life or work experiences.
Please: a) discuss how such factors have influenced your goals and preparation for a career in medicine, and b) describe in detail (to the extent not included in previous answers) your involvement in campus or off-campus activities, paid or unpaid, in terms of community service, assumption of leadership roles, activities related to the care of others, etc.