The basis of Benjamin's paper is the mechanical reproduction of works of art. That is, photographing a painting and mass producing it. This is definitely mechanical reproduction (either through rotogravure or offset lithography), and he uses this model to talk about the context through which you view the image and the then uses that to talk about inherent qualities of the photograph itself. A lot of other writers have used this paper as the basis for a lot of theory, so words seem to be regularly put in his mouth...which I guess is what I'm about to do.
The camera reproduces what is placed in front of it (you can edit all you like, but you still have to place something in front of it - ignoring photogrammes), and it is a machine. In contrast to something like painting, this is clearly mechanical reproduction, and the hand of the artist has traditionally gone unrecognised in photography. It's just as important to understand the language of photography - that is, how a photograph is read and understood - as to understand how to do it. A great example of this is the Avante Garde photography of post-revolution Russia. In a country where the majority were illiterate at the time, massive exhibitions of photographs traveled the country and were used to show what was being done, the progress being made, and as a really remarkable tool of propaganda. The ability for the exact same image to be reproduced a thousand times over is one of photography's most incredible features, and is in stark contrast to other mediums like painting or even printmaking. Efforts to make photographs behave like art objects, through limited editions and so on, are relatively recent.
Benjamin had absolutely no interest in the technical aspects of the medium, just the social and cultural effects of it. He may not have ever taken a photograph.