The following information about Oxbridge Interviews is taken from The Ultimate Oxbridge Interview Guide.

What are Oxbridge Tutorials & Supervisions

Hopefully by this point you are familiar with the unique Oxbridge teaching system. Students on the same course will have lectures and practicals together. These are supplemented by college based tutorial/supervisions. A tutorial is an individual or small group session with an academic to discuss ideas, ask questions and receive feedback on your assignments. During the tutorial you will be pusehd to think critically about the material from the course in nnovel and innovative ways. To get the most out of Oxbridge, you need to be able to work in this setting, and take criticism with a positive and constructive attitude.
The interviews are made to be model tutorials, with an academic questioning an applicant and seeing if they can learn, problem-solve, demonstrate motivtion for their subject. It is by considering this ultimate goal of the interview that you can start to understand how to present and prepare for the Oxbrideg interview process.