Did I say that? It was weird because you are heterosexual. but dude, the wierdest part was NIPPY HAD NO PANTS ON!
Hate to break it to you, but your unicorns have the legs of a human and manes that look suspiciously like pubes.
To answer your question, art directors do pretty much what movie directors do: they define the overall vision for a project, put together a team of specialists, and direct their efforts. In the case of this book, I handled the design of the book (overall concept, typography, patterns, layout, color, binding, etc), and commissioned the text and illustrations (which involves brainstorming with the writer and illustrator, reviewing and approving sketches/drafts, then laying out the final pieces). I've done my own illustrations for some projects (including the poster below), usually collage-based.