Hard to answer. I would try to explain what i mean.
Our objective: shot a short scene where a boy tell his mother that he love her. We can shot 100 different scene's, all different but trying to accomplish the same objective. But some of them can make a big impress on viewer and some not. The one's that make big impression, done the objective and other's not. Because of some criteria, hard to tell them ad-hoc (light, angle of camera, colours, the facial expression of boy, the intonation, the reaction of mom & so on.).