narrative structure. 
The conventional narrative structure can be summed up be the theory Todorov's narrative stages which is, essentially, a complex version of the three act structure. Todorov states that stories start at an equilibrium point, then a disruption to this equilibrium occurs and the main character realises this and attempts to repair it, eventually returning the scenario to a state of equilibrium.


Quite a few of the short films I have looked at follow this structure, though there are slight variations; the most evident example of Todorov's structure to me was in Slap. The state of equilibrium being when nobody knows about the makeup and the disruption occurs when  people start to find out, the attempt to repair comes when he wears makeup to the party however opposite to convention the attempt fails.
Many films have the main three act structure set up with many Todorov narrative arcs in the story to keep the film interesting (for example the main story of starwars is about overthrowing the empire but in the scene where Luke saves Leia we have an equilibrium, realisation of disruption, attempt to repair and a new equilibrium. short films often aren't long enough for these mini narrative arcs within one main one however they show that even a single scene can contain a complete set of Todorov's narrative stages.
Another narrative theorist, Propp, explored character roles within a narrative. having characters that fit in with his character types is a good way to creates a story in which characters have purpose. similar to Todorov's narrative stages people like to play around with the character types within films sometimes combining them or having a nonconventional character filling a role, to subvert audience expectations. due to the nature of a short film there is often not enough screen time for a large cast of characters so a lot of the character types will be dropped and perhaps replaced with other things, a simple example of this is in the fly where we have one character in the getaway driver who we view as the protagonist while the antagonist, instead of being another character, is a fly.


The final of the key narrative theories is strauss' binary opposites; the idea that most narratives revolve around conflicts between two opposing themes, common examples of this are: good vs bad, light vs dark, right vs wrong etc. sometimes, however these opposites are more subtle, in the case of The operator we have potential binaries such as attachment vs detachment or emotion vs professionalism. I think that in the short film format Strauss' binaries can be an effective way to create narrative meaning in the short time frame given.