[jamesgecko]

I was in the demo last year.
Pretty much, they just come and talk to you about the robot. It's not real formal or anything, they just ask you about things in your log book, who did what, why you did things like this, etc. They might point out an interesting mechanism on the robot and ask how it works, they might ask why you did better in one match then in another.

Part of the reason they do the interviews is to ensure that it was the students on the team who did the work and not the adults, part of it is to see what you learned.
Also, I think they simply enjoy talking to us.