... entering the room.

Both mens' jackets do not have vents, and though all pants seem to be deeply pleated; neck ties are way too narrow for the day... and no hats; so I'll rule out USA. The huge, round pillar is interesting; old-world sort of looking... and too few slots too close to the tables suggests a very small room.

I'll go with early-50s Habana as a wild guess... and probably dead wrong.

Have you turned the postcard over?