Faustine
Faustine is clearly a symbol in the eyes of our beloved, paranoid, delusional narrator. She, preserved forever in her beauty by the invention of Morel, represents the elusive, unattainable beauty the narrator seeks. He will never be able to have her, as in capturing her essence for posterity, Morel's invention killed her in real life. Thus she also comes to represent the effects of the pursuit of immortality: a young, beautiful woman whose life was extinguished in the effort to preserve it. Her beauty and unattainability symbolize that of immortality itself.
The Narrator's Invisibility
Through the course of the novel, the narrator realizes that the apparitions can't see or perceive him in any way. Even though in a way their lives are preserved for eternity, their blindness reflects the terrible conditions of this eternal life. The narrator's decay and death, unseen and unnoticed by the target of his affection, draw a horrifying portrait of the effects of the pursuit of immortality, in the case of Morel as well as in his own.
The Walls
Morel's machine projects not only humans, but their environment as well. The narrator discovers this the hard way: when the machine starts up while he's in the control room, the hole in the wall (by means of which he accessed the room) seals up, as the condition of the wall in the time of the recording supersedes that of the present time. The narrator is thus trapped in the machine room, surrounded on all sides by unbreakable walls. These walls symbolize the effects of Morel's version of immortality: there is life, but it's kept prisoner by monotonous repetition and lack of freedom.
Twin Suns
Like the walls, Morel's replication projects another sun into the sky (as the conditions at the time of capture are superimposed on the real-time conditions of the island). This sun beats down on the narrator, who finds the added heat to be stifling and, at times, overwhelming. The pressure and misery inflicted by the extra sun reflect those inflicted by the pursuit and effects of this false kind of immortality.
Charlie and the Subjects' Demise
Morel's experiment has an unfortunate side effect; after the subject is captured by the recording device, it begins to decay, declining quickly into death. The humans, including Faustine, Morel, Charlie (Morel's first subject), and even the narrator by the end of the novel, turn into hideous facsimiles of humans, losing their hair and nails and warping into miserable-looking creatures before death. This physical loss of humanity represents their figurative loss of humanity as they achieve a sort of pseudo-"immortality" that was never intended for humans.
