This prompt has vast potential when it comes to the film itself - I would even go as far as saying that you can go along with it and be as creative as possible.
To give you a brief idea of what this means, the film itself consistently tried to withhold information about the lives of almost all the main characters: Gatsby, Daisy, and the others. If you notice the trajectory of the film, this enabled the film to have a more vigorous plot as you are able to have that notion of mystery ingrained into its timeline. It's enticing for readers to not know necessarily how the film will turn out - because of this, clients would be able to have their own intimate and personalized interpretation of what will transpire in the film. Having an approach like this would let the readers of the text become more interested in the lives of the people.
You can start off from this point of view. Afterwards, you may discuss the specifics of what had transpired throughout the novel/film. Having a detailed explanation, linking them to essential concepts, and creating more visualization and imagery will go a long way.
Best of luck as always!