One thing I tripped over here is just what is a phototube in this context? https://cdn.theatlantic.com/assets/media/img/posts/2016/08/S... "Phototubes protrude from an abandoned building at the Conant Thread-Coats & Clark Mill Complex, in Pawtucket, Rhode Island. (AP Photo/Steven Senne)"
My own knowledge, Google, and Wikipedia have all failed me here. My best guess is it's old slang for pneumatic transport tubes, but I can't say I've ever seen anything quite like what's shown in the picture.