In a live-action project it’s the director who decides what to film. Then just to be safe he shoots a great deal of extra footage. Later he edits that footage, and much of it ends up on the cutting room floor. There is no need for that kind of expensive editing process in animation. No extraneous footage should be produced. So animation scripts have traditionally included the camera shots, as if the writer was directing the story.A finished animation script is still a work in progress with the storyboard artist who follows, improving upon the look of the story. But it’s the writer who initially visualizes each shot in his head.