It was very relaxed, more of a conversation than anything. One of the interviewers actively had my application in his hands while we talked and was picking out parts he thought was interesting and then asked me to talk more about them. There weren't any really difficult questions, as long as you are able to articulate why you participated in specific activities or why certain experiences were important to you. As well as the classic question "what brought you to medicine?"
I also just received my acceptance this morning! So they are very fast with turn-around time.
Best of luck on your interview!