"Companies are looking for art directors with the experience, talent and leadership skills to bring a company's brand and image to life. When interviewing for this position, bring a portfolio of your work and prepare to answer questions about your personal design style, sources of inspiration, and vision for the company's future."
I didn't find any question particularly difficult or unexpected. If forced to chose one it was when she asked how I would react to C-level executive/s shooting down a concept I developed for a seasonal campaign.
I explained that I would be okay with that. That said, I also explained I am diligent and if I felt very strongly that the direction I was offering was paramount for the direction/growth/evolution of the brand, I would fight for it.