Writer's clamp.
No, not writer's cramp.
This is different. Writer's dissatisfaction. I wrote the piece (in my head), but I don't like it. Over and over. It's an important bit to the story I'm working on, even though it seems inconsequential. Why? Because it leads to a more important reveal that can't logically come about without this first scene. Bugger.
I should go write some other part, but this 'simple' segment is annoying me.