Just be yourself and have fun with it. The tests are surprisingly accurate and you'll come out with a better understanding of your individual personality.
You can't really prepare for this exercise just go in cold. I'm overstating this a bit, but a sample question might be.... Do you like guns or poetry? It sounds silly, but just go with it and play their game.
After your debrief with the pshrink, he/she will brief your interviewers while you're waiting and they will taylor your interview based on what the pshrink has advised them. In the big picture of the interview however, the questions you'll be asked are really no different than any other leadership/managerial based interview.