Eisenstein's Montage Trope

Eisenstein covers a ton of ground in his essay "Dickens, Griffith and the Film Today," but for my IQ I'm going to focus on the sections in which he critiques the montage in films made by D.W Griffith and uses it to explain the differences between Soviet and American montage. After acknowledging Griffith as one of the, "genuine masters of the American cinema." (234) he begins to criticize Griffith's idea of montage by saying, "The structure that is reflected in the concept of Griffith montage is the structure of bourgeois society." (234). He then compares his montage to bacon with lines of red and white, representing the haves and have-nots respectively, running parallel to each other; never coming in conflict. And we all know how important conflict is to Eisenstein's montage. He then gets into the differences between the American close-up and the Soviet large scale shot, claiming that "Among Americans the term (close-up) is attached to viewpoint. Among us (Soviets)- to the value of what is seen." (238). Essentially Americans use it to show something and Soviets use it to give meaning to something. He then goes on to write what I'm going to assume is his most important sentence in the chapter, "To the parallelism and alternating close-ups of America we offer the contrast of uniting these in fusion; the MONTAGE TROPE." (240). This montage trope is the key to obtaining new understandings through juxtapositional metaphors; the path to a higher ideological form of film. My question is very simply, what is the montage trope? How is it achieved? Is it simply through the effective juxtaposition of two montage cells (shots) to the ultimate goal of a profound metaphor?