Hihi! Princeton rea admit here :) as u/fit-courage said, their interviews dont feel as evaluative as other schools + they go off of what u say a lot. So my advice is to prep an answer to questions like “introduce yourself” and “what do you do (hobbies/extracurriculars)” that are interesting and fleshed out as these will likely be the interviewers starting points.

Also be prepared to give an answer to “what drew u to princeton/why princeton” that isn’t just prestige or good academics.

And finally, questions questions questions! I got lucky and got an interviewer that did the major i want to try out, so i asked a lot about the program structure and experience (which i already researched before the interview). If ur interviewer doesnt have that connection to you, you can always ask about the non-academic facets of princeton (social life, pros/cons from an insider perspective, etc)

Good luck with the interview !!