Language
The heptapod language is a set of uniquely intricate symbols that hold within them a non-linear context outside of our current linguistic structure. While the English language is interpreted chronologically, in a linear movement from left-to-right, the heptapod's circular written language presents information without a clear chronology.
The film's non-linear narrative structure reveals a key theme: our understanding of language shapes our understanding of time. The recurring motif of the heptapod's circular writing emphasises the heptapod's unique ability to view existence outside of chronological time. As the protagonist Louise eventually discovers, heptapod consciousness does not exist in the linear structures of past, present and future or "beginning, middle and end". Instead, their consciousness is able to experience events in a non-linear manner.
While director Villeneuve celebrates the beauty of the heptapod language, he also highlights the dangers of linguistic misunderstanding. Louise Banks, in her academic writing, observed that language is "the first weapon drawn in a conflict". Later, uncertainty over whether the heptapods want to "offer weapon" or "offer tool" brings the world to the brink of a global crisis. These details further convey another of the film's messages: preconcieved ideas about the function of language can cause disaster. Through this, Villeneuve quietly critiques the modern mindset that views everything, including language, as a weapon to be used against others.
Heptapods
Throughout the film, the cinematography and costume design present recurring images that visually reflect the heptapod's physical form. For example, in the opening scenes of the film, the camera lens blurs to distort humans into heptapod-like shapes. Louise Banks (Amy Adams) playfully chases her daughter while waving her fingers in movement similar to the limb movements of the heptapods. Similarly, her daughter is wearing a horse costume which gives her several extra limbs and again is a visual reminder (or foreshadowing) of the heptapod's appearance.
This visual motif, which cannot be fully understood until later in the film, reflects the way that Banks' encounter with the heptapods has transformed her consciousness. Both the past, present and future are infused with links to the heptapods and their language.
Bomb
Rogue soldiers plant a bomb in the heptapod ship that has landed in Montana. This is a symbol of how many people choose to act out of fear and self-preservation without the proper intelligence necessary to determine if what they believe is a threat is actually one or not. The bomb provides a sobering example of the dangers of viewing everything as a "weapon".
Opening Scene
The opening scene reveals that Louise's daughter has died of an unknown illness. This is a symbol of the great weight of loss of love that Louise must carry throughout the film as she makes every decision.
The bird in a cage
When traveling inside the Shell, the team takes with them a bird locked in a rectangular cage. Canaries were often used in the past by miners to alert them to dangerously low levels of oxygen or poisonous gases. The canary would die sooner than humans, and so the "canary in the coal mine" became symbolic of a moment where danger is first evident.
In the context of the film, the bird in the cage represents both the distrust that humans feel towards the heptapods, and the way that humans are "trapped" within a linear understanding of time.
