Quote from comment section is awesome:
Ok, a few tips: the basic visual detail is now pretty much perfect, leaving you with the ‘next job’ that you need to deal with as a director, which is the ‘human’ side. In close shots, this is all about one thing, ‘reactions’. Just ask yourself three simple questions: what are they looking at? What are they seeing when they look at it? What is their reaction? In close up face shots, this is potentially changing roughy every 4-6 frames. A useful way of kinda ‘cheating’ to deal with the fact that there isn’t enough going on to hold the audience’s attention, is ‘distractions’ tiny, insignificant things going on, like things in the background: this gives a sense of realism when the camera is fixed on seeing what’s happening on faces. But the faces (if there’s two of them) have to be answering questions like this: ‘is the actor either averting or by contrast maintaining eye contact after what was just said or done, by either them or the other actor’ and ‘what are they seeing in the other actor’s expression?’ ‘how is that colouring their own response, their own posture, direction of gaze, facial expression, eye movement?’