The left image is from Hellblazer #173 (2002) in the Ashes & Dust in the City of Angels arc and the right image is from Supernatural season 6 episode 20 “The Man Who Would Be King” (2011).
The reason I not only included a panel from a John Constantine comic but also a shot from a Supernatural episode is because of the coincidental parallel created by the juxtaposed images. The Hellblazer arc follows the story of Constantine’s complicated relationship with a man, S.W., a powerful politician who is in love with him. This was the first arc dedicated to focusing on Constantine’s relationship with a man. The first time Constantine was depicted as bisexual was in an offhand comment in an earlier issue in 1992. S.W. and Constantine have a complex history as lovers and enemies on-and-off. Their relationship changed due to their differing approaches to handling supernatural elements in their universe. This depiction was considered controversial in the 90s not only because it was two men but also because of the overtly sexual element of their relationship, which should not be surprising since Hellblazer comics are marked for mature audiences and sex has been discussed before.
The left panel shows Constantine and S.W. reconciling after another rift in their relationship, Constantine addressing their lingering mutual attraction despite their conflicts. The shot from Supernatural is coincidentally similar to the construction of the panel on the left. Castiel and Constantine are both standing on the left and approaching the men in front of them in front of a multi-paned window, emphasizing their silhouettes. In this scene, Castiel and Dean have a tense conversation about an on-going argument. The mise-en-scène of the scene created by the emphasis of shadows matches the tension-filled atmosphere of panel.
What makes this comparison quite ironic is the fact that Castiel was based on Constantine himself. Supernatural originally intended to include John Constantine in season 4 to be the Winchesters’ guide to the occult, but DC refused to allow the use of this intellectual property so Castiel was created. Castiel’s signature outfit is directly based on Constantine’s trench coat over white collared shirt and tie. The director of this episode, Ben Edlund, has made it known that he has a “manic obsession” with superheroes as demonstrated by his creation and executive production of the series The Tick. His directorial choices when constructing shots featuring Castiel often seem to imitate that of a comic book panel, emphasizing his significant presence though his appearance presents as a human vessel.
A notable similarity between Castiel and Constantine besides their connections with the occult and ensembles is their queerness. In the 15th season of Supernatural, Castiel revealed that the one thing he wants is something he can’t have, in reference to Dean; he says, “I love you,” in a “homosexual declaration of love” (as stated by Misha Collins who portrays Castiel”), which catalyzes his death as this declaration is the moment of “true happiness” that allows the Empty to take him as part of their deal. The unfortunate coming-out scene for Castiel was a core emotional event, contrasting Constantine’s offhand comment about his bisexuality. Both Castiel and Constantine were created as side characters with Castiel originally meant to be killed off. It was never clearly stated that Castiel’s homosexuality was a planned element of his character from the start, but Constantine’s influence on the creation of his character, everything from his outfit to role, appears to have heavy in hindsight implications.
The similarities could be completely coincidental, but the history that connects them is not.