As the young man is first taking a look around the furnished room he has rented, the narrator uses a simile and a metaphor:
One by one, as the characters of a cryptograph become explicit, the little signs left by the furnished room’s procession of guests developed a significance. The threadbare space in the rug in front of the dresser told that lovely women had marched in the throng. Tiny finger prints on the wall spoke of little prisoners trying to feel their way to sun and air.
The simile here—in which “the little signs left by the furnished room’s procession of guests” are compared to “the characters of a cryptograph”—communicates how intentionally the young man is inspecting the room, decoding it the way one would decode a hidden message. This is likely due to the fact that the young man has been searching for his lost love Eloise for the past five months and is looking for traces of her wherever he goes.
The metaphor here—“Tiny finger prints on the wall spoke of little prisoners trying to feel their way to sun and air”—indirectly equates the children who stayed in this room to “little prisoners” trying to escape to the outside world. That this is how the young man views children’s fingerprints says more about him than about the children—he has no way of knowing how they felt about being in this room, but he projects onto them his feeling of being trapped in these derelict conditions. Clearly, he himself feels trapped like a prisoner in this room.
