This was over a year ago, and I had applied for two other positions with the company, and had interviews for all three positions. For that reason, it's hard for me to remember if the graphic designer position had one or two interviews. I only clearly remember one interview as specifically being for the graphic designer position. It took place in a small conference room at a table, and a department head interviewed me. The process seemed fairly relaxed. I presented my portfolio, with all positive feedback. I was asked questions that related to my ability to work with a team, to take criticism, to avoid being domineering, and to be timely with deadlines.
I will call the interview "difficult," not because there was any abrasiveness or high-pressure attitude in the interviewer, and not because I was asked any highly technical questions. I select "difficult" because many of the questions were probing and required some thought in order to answer. The answers tended to boil down to a balance between the ability to contribute as an individual, but not to the point of being self-important and easily slighted.
Also keep in mind, there's a test to take for InDesign and Photoshop. Even though I consider myself expert level at Photoshop, my score was dreadfully low. My InDesign score was very high, even though I consider myself average with InDesign. A person who works in the same position, who also had taken the test, told me the test reflects very little about your actual ability, and it's more of a formality.