It goes by rather quickly. There are two "interview" sections for the MD-only interview process: The "Case-based learning" session which simulates part of the clinical curriculum, and the 25-minute closed-file interview with two faculty members at the same time.
The closed-file interview begins with structured questions, where they ask ~3 questions and only record notes on your responses. No further elaboration or reaction to your answers. Once those are out of the way, the rest of the interview becomes more of a dialogue, going back and forth and so on.
The Case-based learning can last about an hour and takes place while other applicants are going through the 25-minute interviews. Here, several applicants are grouped and moderated by current students. You'll examine a case as a group and discuss it, trying to answer the questions related to it and learning more as the case goes on. Emphasis is given on how you work as a team, rather than whether you get it right or not. The students are able to clarify medical topics if there's info that isn't clear, since you're not really expected to at this stage know all of the ins and outs of the case.
The rest of the interview process includes learning more about the program, the location, and overall it was a relatively stress-free experience. All of the faculty and students were extremely friendly, easy to talk to, non-judgmental, and eager to hear more about you. I know it's easy to get stressed out during an interview, but they make it very easy to build rapport and before you know it, the interview is over and I found myself wanting to keep going a bit and talking longer with them. Nothing to worry about at all, I think you'll find this to be a very smooth interviewing experience