Just experienced this at an interview last week- for us, the questions they asked were your typical structured interview questions (e.g., why x school?, strengths/weaknesses, tell us about a time when...) and the questions I asked during my time with the non-POI were program or school specific. She was also very aware that she wasn't my POI so in the answers she gave me, she referenced my POI and talked about how the answers related to the school generally and to him. Msg me if you want to talk in more detail!