Reminds me of thumbnailing, which is sort of proto-composition, proto-construction and proto-gesture all rolled together. Which makes me think of the fact that gesture typically refers to the posture of an animate creature, but can usefully be applied to any organic object (and arguably many non-organic ones, or even the picture as a whole.).. and wonder if you are going to point out in the gesture entry that gesture is not restricted to animate things.
Yeah, Gesture really works for anything organic or not. I think the specific term Gesture however came from figure drawing, living creatures and animation so it should refer to that even if it is related to the "other" use. Not sure what the other use is called though: Maybe Rhythm & Flow = Gesture for everything which is not a living being?
I thought Thumbnailing is the same as sketching/doodling but on a very small scale to figure out composition/partitioning/placement/etc. quickly and to make lots of iterations fast without having to worry about the details that go into creating a polished artwork from it.