Last year I didn’t have any interviews and this year I had one for visual arts and one for art history (dual degree program, but these two weren’t for the same school). I usually ask about what’s important for me like facilities, funding, teaching opportunities, and jobs post-grad, like what are their alumni doing. It’s always good to ask questions! You can even ask them to be more specific on something they mentioned during the interview.
Also, just because you don’t get requested for an interview, doesn’t mean you’re not getting in! Unless they specifically say on their website they do interviews, some programs just do not interview! The one I got into last year didn’t do interviews.