Brokeback Mountain

I Just finished an essay I had to do for class.
The essay was about one of my favourite movies: Brokeback Mountain.
Here is the essay question:
What differences of signification, if any, are introduced by the visual style of the adaptation relative to the meaning(s) of the text(s) it is based on? In other words, to what extent have the visual choices made in the adaptation modified and/or enhanced the meaning(s) of the original text(s)?

I argued that the meaning of the film was enhanced by the image, acting and music.