It was much more laid-back than I expected. Definitely wear a suit/interview appropriate clothing. There will be a few information sessions to start and the interviews are later. They split us up and assigned 2-3 prospective students to 1 faculty member who would interview us.
The faculty member chooses from questions in a packet they are given. My interviewer asked us each the same questions one at a time and took notes on our answers, but it might be different depending on who interviews you. I was asked questions like:
1. Tell me about your background and how you became interested in PT?
2. What extracurriculars did you do in undergrad?
3. How have you improved your application since applying to schools in the past?
A few others that I can't remember. Pretty much simple questions, though. My best advice is to treat is as more of a professional conversation. Prepare yourself for all the basic questions, but its always good to know how you would answer some more difficult questions too. Also prepare a few questions for the interviewer because you are also trying to see if the school is a good fit for you. It sounds like they "score" your interview, as well as your other application components and use that overall score to help determine who they choose. Hope that helps!