Most common experience a director has in the editing stage is staring at the screen and wondering why he did not insist that the actors do more. There it is again more, rather than less. The raw material he uses is no more and no less than what the camera recorded and what the actors put into the lens. The editor often start off on one person, and then look at the shot of the other person listening, to see if there is anything of interest going on. When an editor/director is cutting from someone speaking to the person listening, he often only wants to take a second or so of the listening shot to liven up the talking shot. Continuity always astounds screen people that an actor can act a speech one way and then a few minutes later do the same speech with the pieces of business in different places.