I just finished watching Fritz Lang's Metropolis, in a word stunning. Amazing that this is now 80 years old. The breadth and depth of Mr. Lang's concepts are extremely complex and varied. To start I wish to say a few things first that are not necessarily pertinent to our Cyborg discussion specifically. The two elements that caught my attention as the movie moved along were the religious and political (or perhaps economic rather) ideas. The parallels and Christian themes and allegories are fairly self-evident and I will return to comment upon those in a moment. In the beginning of the movie it seemed to be echoing Marx's ideas of the dehumanization of man by industrialization. The machine is portrayed as an entity of its own which survives and lives on man, i.e. the laborers. The machine at one point early on is called Moloch, which can be a type of deity or evil master. And in this case it seems Mr. Lang is definitely saying that technology is (or can be) a cruel and evil master.
The main (overt) theme of the movie is that the hands, i.e. the workers (or the proletariat) and the head (or the bourgeoisie) can only survive if they are united by the "heart" or the mediator, which given the movies religious/Christian overtones could be a direct appeal to Jesus and the message of the Gospels and New Testament, that being the message of the heart, one of love, forgiveness and compassion.
As the movie went along a theme that came to my mind was the fact that the masses, both the bourgeoisie and the proletariat, but especially the proletariat, or the hands need to be lead. In the beginning of the movie they are lead in a dehumanizing manner by the bourgeoisie, then there are lead by the hopeful Maria, then they are lead by the automaton/machine Maria (HEL), then the are lead by the worker who was in charge of the "heart" of the machine, until finally at the end of the movie I was wondering who or how they would be lead now. It seemed that the entire movie kept implying that one way or the other the hands, the workers must be lead, as a group or as a heard, but they must be lead. Perhaps Mr. Lang had a classical Greek idea in mind implying the importance of the group over that of the individual, or perhaps a more socialistic one I am not sure. But outside of the "individual" that is the mediator, the Saviour (and Mary, which begs for the interpretation of either Mary Magdalene, of the Holy Mother Mary) the emphasis is on how the group reacts and responds as a whole.
The one machine that represents the idea of the cyborg, is named after a women named HEL and is first presented underneath what looks like a cross (no pun intended) between the Star of David and and inverted Pentagram. So the only female of the main characters in the movie, Maria is portrayed as both the good (human) Maria, and Maria (HEL) as the bad (machine) Maria can be both good for the proletariat or bad, and apparently the choosing is not always easy. The human Maria represents love, peace and hope, whereas the cyborg Maria, represents violence, hate, and destruction.
It is not clear to me how Mr. Lang at the end of the movie wishes us to envision Metropolis moving on. It is clear that he seems to intend that it will continue on in a positive direction but the how is entirely unclear matter. Perhaps, somewhat like the Marxist (or perhaps Leninist) idea that the details will be worked out exactly what to do only after the revolution happens, which has always seemed a bit problematic to me.
Also unclear at the end of Metropolis is exactly what will be the relationship between technology/machines and humanity. In the end it seems that he is at least gives us an optimistic point of view that there is hope for the future even if the path to get there will be difficult.
The themes and images that Mr. Lang uses in in his epic masterpiece require a much more in depth study to come to a fuller understanding of Metropolis in all its magnificent complexity. And what I have put forth here is a first impression and a mere scratching of the surface of all the ideas and concepts that the movie deals with and portrays.