Congrats on the II! We'll meet in person if you come the 14th or 28th.
Interview style is conversational, one-on-one with two different ad com members. Super chill, laid back. Questions you would expect--why do you want to be a physician, what interests you about our school, questions about your education and experiences...We also talked alot about common interests. For example, one of my interviewers had a son who was starting residency at the university I had just attended for undergrad, so we talked about the city and the school for quite a while. Talked about the nearby places to ski and whitewater raft in WV. Nearly everyone I've met had a favorable interview experience.
It's been a few years now, but I believe the interviews were about a half hour each. They went by quickly and were actually quite enjoyable. Laughed with both of mine. I got the impression that they had already decided they wanted me, as much of the time was spent telling me about the program and answering my questions. (Definitely have some questions ready.) Other OOS people said they felt the same. Makes sense if you think about only maybe 75 or so out of over a thousand applicants being offered the OOS II's, they probably are considering you a highly desirable candidate before you even get here.
Best of luck!