One literary device that El Notre seems to deploy is symbols. One symbol that you might focus on is the Good Housekeeping magazine. The periodical seems to represent the good life for Rosa and Enrique. It provides them with hope and a sense of what’s waiting from them if they can reach America.
If you think about the symbol of Good Housekeeping closely, then you might also infer that it symbolizes the artificiality or falseness of the American dream. Like the magazine itself, the concept of America depends on carefully presented images and rhetoric that doesn’t reflect the reality of the situation.
Another literary device employed by the movie might be foreshadowing. Early on, the father is killed. You could say that his death sets the stage for the kind of suffering and hardship that Rosa and Enrique endure throughout the movie.
As for colors, you might have noticed how dreamlike and natural the colors are when Rosa and Enrique are in nature. That warm, organic color contrasts with the scary, frightening colors when they’re trying to enter the United States via the sewer drain. You could say that the movie encompasses many moods and emotions. The diverse colors reflect the various feelings and predicaments in the film.
As for shots, you might have noticed a fair amount of close ups on the faces of Enrique, Rosa, and the other Latin American characters. The close ups might be a way for the filmmakers to emphasize the characters' humanity and individuality. Sometimes, like in the factory and in the wagon, there’s far-away shots. These shots might help the directors show that Enrique and Rosa’s situation is not uncommon. There are many other people suffering alongside them.