Surrealism is a good term to apply to Kafka’s work, because etymologically it means “above realism.” In the early 1920’s artists and writers experimented with alternates to realism, the prevailing mode prior to World War I. Surrealism is often referred to as “literature in the dream state,” where a different kind of logic (or non-logic) prevails (as we all experience when we dream disjointed but strangely detailed events). If we remember that Georg Samsa wakes up “from a restless sleep” to discover that he has taken on an exo-skeleton “beetle-like” shape, we see that Kafka is inverting the relationship between so-called “reality” and the dream-state. The key to understanding this reversal is remembering that strange dreams come from “anxieties” that cause “restless sleep”. In the 17th century Spanish Calderon wrote a play entitled Life is a Dream (La Vida es Sueno) in which such a role reversal is manufactured, to make the same point—that our daily “logical” life could be a dream. Georg Samsa “wakes” into the surrealistic dream world where apples stick in his casing, etc. Kafka is using this surreal device to question the assumed cause-effect “essence” (as opposed to the “existence precedes essence” idea of existentialism) of life. If you read the whole story as a recital of a dream Samsa is having, you will be much enriched by the layers of narration Kafka handles here.