No, not writer's block, but writer's blocking. I learned this from Eric Puchner last fall and it's helping me in my never-ending quest to slow down and unpack. (Ann Patchett says that a teacher once compared her work to "concentrated orange juice" which needed water. I have the same problem; it's nice to have something in common with Ann Patchett!) Anyway, blocking is basically what they do in the theater. Where are the characters? Who's standing where and in what relationship? How far is the floor lamp from the vampire's coffin? I'm now beginning to see why some writers physically sketch out scenes, even storyboard them. Of course one doesn't want to go overboard: "She stood in the middle of the front lawn ten feet away from him (with her on the lower left end of a diagonal line and him on the upper right). Her gaze was aimed perpendicularly to his, so that in order to speak to him, as she will as soon as I'm done explaining the blocking, she had to turn her head approximately 45 degrees. Because she was angry at him she chose not to face him directly, and she turned her head without moving her feet, which was awkward but she had a stiff shoulder from sleeping on it the wrong way the previous evening (also due to anger), and besides the grass was slippery from the dew (it was morning) and she was afraid of losing her footing." Yet the writer does have to have such a clear physical picture of every scene, and how the characters move through it, in her own mind.
Lately I've been looking at houses on distant hills (because I'm writing about someone who spies on people in such a house through a telescope) and trying to figure out how far away they actually are and how high up. The question adds certain dimensions, as it were, to the story--I begin to wonder how long it would take the spy-ee (once he's discovered the spy-er) to drive down the hill in a rage and bang on the spy-er's door. All this does help add texture and create a sense of being there in the story. So I hope, anyway. I've always tended to leave my characters suspended in the air, not being especially interested in setting on the technical level. But now I'm beginning to see how setting, and specifically blocking, have their own ways of driving the story.