I use a broader definition of art direction than the guilds in Hollywood.
I could call it Production Design, but honestly, we’ll call it that when it’s appropriate. Art direction is what they called it back when movies were “pictures” and the credits only lasted three minutes.
I use the term to describe everything you see in the frame of the finished film that isn’t a human being. For example, if I decide we need to shoot your film in the conference room because I like the potted plants, that’s art direction.