R2 applicant here. I've completed the two interviews. Neither interviewer had anything in common with my background nor my post-MBA aspirations, which I found odd.
Both interviews were very laid back and conversational and were completely focused on INSEAD, my interest in the school and how I felt the program would help me achieve my goals. Neither one tested me on my other two languages. There weren't any questions that dug in depth into my work history. No questions such as, "tell me about a time when you exhibited leadership," or "when have you had a difficult time dealing with a coworker and how did you handle it?"
I way overprepared for the interviews, which is a better problem than underpreparing, especially since there seems to be quite a bit of variability in style.
Now it's just time to play the waiting game.