The week before the event they sent out the reviewers and I got to pick my top 12, and I, for the most part, got all the people I wanted to see which I was worried about. Once I got my list I looked up each reviewer and started writing down specific questions I wanted to ask each of them. Some generic questions I asked were:
"What do you look for in the photographers you hire?"
"Do you think I'm ready to shoot for you? And if not what needs improvement?'
"What are things you've done in your career that have helped you stand out?"
I would also try and ask one specific question to that reviewer, mostly revolving around something that I saw they worked on and wanted to know more about.
That being said you only have about 15 min with each person and that time usually goes very quickly. I was more interested in hearing what they had to say about my work than asking my questions and a lot of the times the conversations flowed very easily, but for those that weren't as smooth I was glad I had some stocked up questions prepared, anything to keep them talking either about themselves and/or my work and stay interested in me.
There is a lot of downtime in between meetings so you just hang out with a bunch of other photographers and look at their books and talk photography which was so fun. It's much more relaxing than I pictured it was going to be which was great and the man running everything there was super nice and did his best to get you into meetings that maybe you weren't originally able to get into. They had food and drinks, Sony, Fuji, and Hasselblad all had tables set up where you could talk with reps and play with cameras as well.