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.

“And it only takes a week and a half, from start to finish!” /s

Funny to think how archaic this looks by modern standards. One photo taking up a roll bigger than your fist? We’ve come a long way with just a century of progress.