I agree with Gene Dougherty that we interviewers serve as ambassadors for Princeton. In my invitation email to students, I write:
“This informal interview has two main purposes:
1) to add a fresh dimension beyond the information in your application, for example enlarging on an area that you feel comes across better in person than on paper, and
2) to give you an opportunity to find out more about the Princeton experience than just the information on the Princeton web site and information booklets.
In a nutshell, we volunteers serve both as an advocate for you to Princeton and an advocate of Princeton to you.”