The suffix -gram is derived from ancient Greek:  (gramma), meaning something written, i.e. telegram means something written at a distance and cablegram means something written via a cable, whereas telegraph implies the process of writing at a distance.

The word "telegram" comes from the Greek words "tele," meaning "distant," and "gramma," meaning "letter." It refers to a communication sent over a distance, usually via a telegraph system.

In short, the voice is an evil entity 'playing' with Kevin and Kaylee. Kaylee doesn't play by its arbitrary rules and is removed. The repeating cartoon disappearance shows exactly what the entity is doing to Kevin, tormenting and mutilating him over and over again for its own amusement, for 572 days and into infinity.

The Big Picture\n\n The movie delves into the theme of childhood abandonment or abuse, portraying the home as a place of terror and hopelessness.