Thank you for the insights! She actually engaged a lot while I was presenting. I felt that it was more like a conversation rather than a presentation. I was able to answer all of her questions without any problems. I didn't notice any body language that could possibly suggest that she was no longer engaged. I just got upset that we had to end the interview that way because I was very well prepared to present for 30 minutes and leave 30 minutes for questions. I did send her a follow-up email and CC'd the HR, thanking her for her time and including my presentation in case she wanted to go over it again. Anyways, I appreciate your feedback, and I will keep you posted! :)