The Book
More accurately, this symbol might be entitled "The Book Within The Book Within The Book, and All of the Above," which might be more in keeping with Lerner's pretentious prose. The narrator's short story/novel, and the character in the novel's own short story/novel, as well as the actual book 10:04 as a whole, represent the products of creation in this shifting, uncertain world. It's confusing, but it's an homage to life and reality, a small microcosm of the macrocosm of the world, an attempt to encapsulate the essence of life into a 256-page manuscript forced into some semblance of chronology. The book also represents the author's own work as a whole.
Alex's Baby
The main character's best friend, Alex, wants more than anything to have a child. Her obsession with creating life mirrors the narrator's obsession with creating art, and the parallelism there implies that these desires are almost the same. The narrator puts his own dreams on hold to fulfill Alex's, and the life that he creates seems to take the place of the book that is in the process of creation. The baby is a symbol of the glory of creation, both of life and of art, in the turbulence of the world.
The Photograph
The photograph that makes up the book's cover artwork has a specific plot function. The author, interjecting himself into the novel and breaking the metaphorical fourth wall, says that he took the picture in New York, and it represents everything he's trying to convey about the city. This photograph captures a bit of what the novel is attempting to encapsulate: life in New York.
The Narrator's Heart Condition
The narrator learns, in the course of the novel, that he has an unstable heart condition that will have some unknown impact on his life. This condition is always in the back of the narrator's mind, a backdrop against which the action is set. This heart condition is a symbol for the uncertainly of life, highlighting the narrator's point that we must go on living and enjoying despite the terror of uncertainty.
Alena/Hannah
The narrator's sexual partner and pseudo-girlfriend-figure, Alena (or Hannah, depending on which version of reality you want to talk about), is a symbol for the type of common relationship in today's world that is purely pleasurable or functional, not one undertaken for its own sake. She doesn't care about him as a person, and jealousy is a foreign concept. Their interactions are more like transactions. The failure of this relationship is a message: these friendships of usefulness are neither worthwhile nor sustainable.
