My PCO interview was very relaxed. They asked the basic questions: why I wanted to do optometry, what I liked when I shadowed, whether I was more interested in private practice or commercial (something like that), what I liked about the school, etc. But mostly I just talked with the interviewer about the kinds of films and books I like and about my hobbies. I thought that it was important to show my actual personality and give her the sense that I can connect with people. I felt really confident after the interview. So...just be yourself. Make eye contact, joke a little bit, and talk about current events if possible (show that you're not just in a study bubble). Be natural.