Thing is, though, that I can't find a branch-line terminal station in New England that fits. I looked at every one that I could find online, and all the old topo maps, and either the station building looked wrong, or the layout of the surrounding village- road up a hill to the left of the tracks, another road crossing the tracks in the distance, a store/gas station by the level crossing, a church or grange hall up on the hill- was wrong. That's what lead me to think that maybe we're looking at a through route that's being downgraded-- which is why I got excited about Allerton Farms, on the old NY&NE over Towantic summit, since it had a loading platform that matched... but, as you say, that station didn't have a hipped roof.
Several things about the picture make me think we're looking at the 1920's or '30's, 40's at the latest. One, the sepia tone itself-- I can't say for sure, but I think that was long out of fashion by the time of the Second World War: we have plenty of old family snapshots from the '30's and they're all normal black & white. Second, the wood plank platform: post-WW2, it seems to me most ground-level platforms would have been asphalt, not wood. And third, the rail: hard to tell exactly, but that stuff sure looks light- maybe 75lbs?
So, if not the line over Towantic Summit, could we be looking at someplace on one of the Central New England lines west of Canaan? Maybe a couple years before the New Haven pulled the rails in the late 1930's?