I interviewed at Touro CA which does group interview, and it was an interesting experience. There was a DO physician, a Ph.D and a 2nd year student. The interview was about an hour long, and there were four of us in the room. So each one roughly had 15 minutes. Each asked different questions, but the student asked the toughest questions to the interviewees. For example, he asked a question to one of the interviewees "It looks like you don't have any clinical experience. What drives you to become a physician if you have never experienced a hospital setting?"
Overall, the group interview at Touro was very much like 1:1 interview except there are other interviewees listening to your answer and you are expected to listen to their answers as well. After all, they can be your friends in med school in the next four years.