In a gesture drawing, a whole arm that didn’t matter much might be just a smudgy slash, while a line that captured the twist of a spine might stand in sharp, carefully observed relief. The “gesture” was the line of organic connection within the body, the trace of kinetic cause-and-effect that made the figure a live human being rather than a corpse of stitched-together parts. If you “found the gesture,” you found life.
What is the essence of what you see? No measuring! Quick!