I love indoor shots, especially when they show how photographs were displayed. These three students are most likely standing in their fraternity house’s common room or dormitory. Besides the three subjects there are three cabinet photos on the dresser behind them, with a clock in the middle. In the mirror above is the reflection of a cuckoo’s clock on the opposite wall (a little hard to see unless you use a looking glass). There’s also a display of real photo postcards on the back wall; street views, mountain views, greeting cards. I can’t help but think this was their “Facebook wall”. :)
And you have the lace curtains on the window along with their two banners, one facing indoor and the other facing outside for everyone to see. The last word on that one looks to be Merris.
The RPPC is divided with no stamp box. I believe this was taken in the mid to late 1900s.