Another benefit to these kinds of pairings is they inspire you to approach cinema history more imaginatively. When you find common elements across different films, you're inclined to grant them greater significance than you would have otherwise. At times, you stop thinking about creative intent or the role those elements play within each film—you start thinking about cinema as a great, holistic thing that inflects certain objects or situations the same way every time. It doesn't matter who's behind the camera or what's the general tone of the movie.
I remember one binge when a friend and I tackled Roberto Rossellini's L'Amore (1948) and Jerzy Skolimowski's 30 Door Key (1991) in the same night. We referred to them afterwards as "goat movies," since both featured goats at some point. Goats played a less prominent role in Skolimowski's film (indeed, I no longer remember what they did in it), though the symbolic power granted them in L'Amore (as representatives of natural beauty, stubbornness, simple-mindedness, etc) carried over just the same. Too bad this happened before La Quattro Volte (2010) came out. Had we made that the third film in a triple feature, it would have been buttressed by the impact of the other two and seemed like a milestone in goat cinema.
In his 1967 book Films and Feelings (one of the most imaginative works of film scholarship ever written), Raymond Durgnat writes, "There is a vast repertoire of vivid and valid symbols which spectators understand without thinking of them as poetry. Whether they are convincing or not often depends on the accompanying richness of detail." He goes on to offer "a little dictionary of poetic motifs," which includes such gems as:
Carnivals. Like the fair, it is a sudden explosion of caprice, of desire; it is fate, destiny, because it is visual fireworks of impulse and instincts. In fancy-dress the characters, consciously or unconsciously, reveal their 'real' selves, their hidden aspirations. The ingenue masquerades as a vamp, timid M. Hulot [in Mr. Hulot's Holiday] as a pirate. The tragic figure wanders through the revelers, who jestingly but carelessly buffet him—just as the clown is traditionally a tragic figure because any seriousness he can feel is mocked by his own comic mask.
Getting back to the Doc Films double feature from last Tuesday, I encountered across the two films a poetic motif of the factory. In the second "movement" of Enthusiasm, the steelworks represents collective endeavor at its best. Vertov cuts between images of human effort and of big, new machinery in operation, suggesting that the former achieves its apotheosis in the latter. For this communist poetry to have any emotional effect, Vertov must illustrate what each machine does, so as to create a sense of continuity between people and industrial production. Without this link, a steelworks is an imposing, even alien-looking environment—in other words, it's only beautiful if you can imagine yourself as part of it. When an Ontario steelworks appears in an early scene of Clean, it's across the river from where Maggie Cheung parks her car to shoot up heroin. It's an inhuman backdrop for a scene of isolating, self-destructive behavior. It stands in for a number of communities from which Cheung feels alienated: the world of rock music, her husband's family, Canadian society in general. It's hardly a shock, a few scenes later, when she comes face-to-face with death.