Had the two photo machines been directly coupled over the line, the image wouldn't have had to be digitized at all, and you would expect a considerably higher quality image. But getting the image onto paper tape allowed for the photo processing setups to be in different locations from the transmission gear, and used at diffrent times. The actual transmission of the data could go over the normal infrastructure whenever it was convenient to send it, substantially increasing the throughput of the line.
The bottom blurb does a bit better in terms of explanation, but yeah. I spent a while myself going over it, trying to discern the functions that they were attempting to illustrate. Still not entirely sure on the reproduction part, but it seems to be sort of "printing" the data onto the fresh film?
