Ava (Symbol and Allegory)
Ava, in addition to being a character in the film, is also a concept—a symbol for man's desires and his impulse to create a machine that mimics consciousness. She is the "ex machina" of the title, a trope in classical literature in which a god appears in the final act of a narrative to bring about the outcome of the story. Here, the trope is also specifically gendered: Ava represents Nathan's (and by extension, Caleb's) desire for some kind of ideal woman—a naive, programmable machine that appears to have a consciousness of its own, but is completely controllable through technological programming. In this way, she and the other robots become symbolic of the subjugation of women in society generally, women who are forced to be in servitude to the men in their lives. Ava's striking back against her captors and escape from the estate represents not only a robot's rebellion against its creator, but also—because of the gender breakdown in the story—a woman's escape from an abusive situation.
Ava is a complicated symbol, in that she alternately represents femininity and technology. By the end, she reveals herself to be a sociopathic and unfeeling machine, only capable of mimicking human emotion. In this light, she is a kind of Frankenstein character, a machine that has become aware of its own captivity and fights back against her maker. In another light, she is a stand-in for Pygmalion's statue, a woman who is sculpted by a man to be an ideal, with whom he falls in love.
The Ripped Up Drawing (Symbol)
About halfway through the film, Caleb witnesses an interaction between Nathan and Ava in which Nathan appears to act abusively towards the AI, ripping up a drawing of hers. Cakeb later learns that the drawing was of him, and becomes even more sympathetic towards Ava. In this moment, the drawing symbolizes, to Caleb, Ava's affection for him and her desire to be with him. He takes Nathan's action to mean that he is jealous and abusive, which only encourages Caleb in his quest to rescue Ava from her ruthless master.
Punching the Mirror (Symbol)
Later in the film, when Caleb has become overwhelmed by what he has learned about Nathan's seemingly exploitative operation, he begins to unravel. Falling more deeply in love with Ava and confused about what makes her an A.I. and him a human, he begins to become paranoid and upset, cutting his wrists and eventually punching a mirror in a rage. This moment of Caleb completely losing his calm and stability, represents the fact that he is losing his grasp on what makes him a human. He is frustrated by the artificial reality of Nathan's facility. Is Ava a person? Is she deserving of sympathy or affection? Is she capable of emotion and affection? What makes Caleb a person and not a machine? Caleb's breakdown is symbolic of his coming to a boiling point with all of these questions, overwhelmed by his own limitations and the emotions that have overtaken him.
Nathan's Drinking (Motif)
Throughout the film, Nathan exhibits an indulgent relationship to alcohol. When Caleb first arrives at the facility, Nathan is nursing a hangover from a solitary bender (there is no one else at the facility). Throughout, Nathan drinks to numb his own loneliness and alienation, as Caleb watches him. Nathan's drinking problem becomes his only weakness in Caleb's eyes, an avenue through which Caleb is able to manipulate the CEO and change the security system in the facility. The drinking represents Nathan's desire for escape, his dissatisfaction with his life, in spite of his power and wealth.
Ava's Body (Symbol)
For the entire film, Caleb (along with the viewer) tries to discern the exact nature of Ava's personhood; is she simply an advanced robot, or a thinking, reasoning, feeling being that might qualify as a person? Garland emphasizes this dilemma in his presentation of Ava's body: rather than being fully metal or fully humanoid, she is an intriguing blend of half-human, half-machine, a humanoid plastic-based creation with the face of a woman and the ability to don human skin like a sleeve. This body is a physical symbol of the dangerously tricky question Caleb (and the audience) must wrestle with, and all of her alluring contradictions.
