The arched windows remind me of several old train stations I've been in. Also reminds me of some of the old factories that had arched windows like this, often to let a lot of light into a factory floor. Likely this is a second story office. Could be a retrofit to make more efficient use of all the lofty space or could just be the arched window design was desirable for the exterior of the building regardless of where there wasn't an open atrium.
Judging by how dark it appears to be outside and the clock showing just after five, it could be winter just after quittin' time, though the cut-off sleeves of the one woman's outfit would suggest warmer weather and longer days, so I lean toward five in the morning, which lends credence some kind of night or early morning shift.
Each of the three visible copyholders has some kind of table in it
There are at least two individuals in the office-- the women in these photos. Looks to me as if they took turns taking photos of each other, otherwise an onlooker would have likely taken a single photo of them both, plus the lady at the closer station is not sitting in her chair in the photo of the lady at the farther station.
The two stations we see the two women manning (yes, I said manning) are the only ones that have paper in the take-up roll. This suggests to me that these two women (or two other individuals not in either photo) had actually been working prior to the time the photos were taken and that the other stations were not in active use at that time of day. I would guess these women actually worked in this office, otherwise why would they take glamor shots at two different stations? Why not take turns at the nearest station?
I agree that the machine on the other side of the counter appears to be a 28 RO. There appears to be another 28 farther back in the room next to the second closest station, or perhaps the third station, much like the first 28 is lined up with the closest station. Each station may be equipped with a dedicated RO machine for purposes of incoming messaging to each operator.
Just behind the shoulder of the woman with glasses looks to be some kind of rolodex, and it's situated for her to easily look at and access while working at her station. I'd infer that each station has a similar rolodex. This might give a clue for what kind of work they might be doing-- something that would require looking up names, numbers, addresses frequently enough to warrant a rolodex for each station. Or perhaps there is other information aside from the typical contact variety on the rolodex cards these women would need to frequently reference in their daily work.