The Irony of Disatisfaction
The caveman is devoted to his role in this living display. It is his entire life, essentially, except for a few brief breaks in which he smokes, chats with fellow employees, and receives his paycheck. As his job may suggest, he is not exactly a people person. For this reason he resents Janet. Since she is not as thoroughly engrossed in her role as he is in his, he also hates her for reducing the legitimacy of his part. He spends all of his free time eagerly denouncing Janet to management, but when the replacement comes she is demonstrably more committed to the role than even this nameless protagonist. She has surgically changed her face to resemble a prehistoric human, something which the caveman has never before considered. Ironically, while he longed for someone devoted to the role, he is now threatened by that very thing being given to him.
The Nature of Truth
Greg serves the role of mediator in the protagonist's life. As Janet and the caveman's employer, he is an authority figure. Additionally he serves a more directly mythological role for them as provider, being responsible for their food every day. When the food stops appearing, it represents Greg's fallibility and potential untrustworthiness. He appeals to the caveman to determine whether Janet is eligible to remain at her job, making the additional point of contention of pitting his employees in competition with one another. He allows the caveman to become the mediator of justice, in this case, against his co-worker. This explains the rather vague and disturbing note which the caveman receives before Janet's replacement arrives. Essentially he is being taught that, in Greg's judgement, truth is relative. What the caveman considered fact, is a limited perspective upon Janet's performance. He thought he would be better off without her, but now his job is threatened by her replacement.
The Absurd Nature of Employment
By placing Janet and the protagonist in a living display acting as prehistoric people, the author has made them into caricatures. True, their jobs are part of the plot, but more than that the nature of their employment is so absurd and unrealistic that it illustrates a greater point about employment in general. While Janet and the caveman pretend to be cavemen, they push aside the rest of the world in order to fully embrace the roles. This looks like Janet not having heard from her son for so long that she didn't know he was in jail. Their roles are so demanding that they have lost their social identities. As Janet clings to her "real life," she further alienates her co-worker who has abandoned all ties to the material world for the sake of this job. The job itself has become the illusion, not the acting. For the protagonist, his employment is his life, something more important than all other aspirations or pursuits in life, which has caused him to fear unemployment more than any other human value, especially loyalty or love.
