Meaning of Stahr's story to Boxley during their meeting

Towards the beginning of the film, Stahr (Robert Deniro) has a meeting in his office with the British writer Boxley (Donald Pleasance) and the 2 studio writers he has assigned to work with him. Boxley is not happy - he calls the other 2 writers hacks - and it is clear that he, although a successful author, is new to writing movie scripts and does not like both the script doctoring he is doing (Stahr: "Would you write something like this in one of your own books?" Boxley: "Of course I wouldn't! I inherited this absurd situation.") or movies in general - he "rarely" goes to movies because people "are always talking a load of rubbish." Stahr then, on the fly, describes and acts out a scene in which Boxley is resting in his room, then a girl comes in and does a series of things without noticing him, and then a man is suddenly seen there closely watching the girl. He then sits back down at his desk and Boxley asks him "What happens?". Stahr says " I don't know, I was just making pictures." I don't quite understand what Stahr's point was. Was it to show a frustrated and discouraged Boxley that there isn't really that much to writing movie scripts and that it isn't hard to get and keep the audiences attention? Obviously it doesn't ultimately work, as Boxley later self-destructs. But was that his point or was it something else?