So I had my interview a couple weeks ago, and I want to share a bit about my experience to help people out in the future.
First, it is totally true that it is more small talk than it is an academic interview. I got some bad advice from a professors of mine to prepare for stuff like.... "What do you think of the Supreme Court's decision to take the Obamacare case," "Describe your favorite literary book," stuff like that. It was totally not like that. They asked me stuff like:
Describe a time I resolved a difficult situation as a leader
How I define success
What I've learned from my current job
Curiously, they did not ask me anything about why Harvard. Like, I didn't expect them to actually say, "so, why Harvard?" But I at least expected them to ask it indirectly in some way... But whatever. If they actually asked me why I want to go to Harvard I would probably have just started laughing anyway, so it probably worked to my benefit.
Additionally, I wanted to post because no one has really talked about how the pressure of the time gets to you. They tell you at the beginning you only have 15 minutes, and that got in my head--I started getting nervous that my answers were taking too long, so I rushed through them and I think this messed me up a bit.