"A Sound of Thunder" Bradbury employs metaphor, simile, parallelism, irony, and paradox.
In the exposition of the story Bradbury writes in metaphor and simile, using parallelism to enhance the poetic quality of his diction:
Eckels glanced across the vast office at a mass and tangle, a snaking and humming of wires and steel boxes, at an auror that flickered now orange, now silver, now blue. There was a sound like a gigantic bonfire burning all of Time, all the years and all the parchment calendars, all the hours piled high and set aflame.
This use of such poetic devices lends a tone of almost Biblical importance to this science-fiction story as the reader is reminded of the story of creation in the Book of Genesis, although in reverse: "A touch of the hand and this burning would on the instant, beautifully reverse itself." The use of the word snake certainly recalls the serpent in the Garden of Eden and the evil presence there. Of course, the foreshadowing of evil effects in the return to the Dinosaur Age cannot be missed with this allusion as well as the allusions to fire and its potential for destruction.
Furthermore, that there is a distortion of the natural order of things as suggested with Bradbury's use of paradox. In fact, the character, Lesperance even uses this word when he responds to Eckels question about the guide's earlier time-travel trip meeting Eckels. "That would be a paradox. Time doesn't present that kind of mess," a foreshadowing of the story's end. Examples of paradox then appear as Bradbury writes of the "gliding ballet steps" of the T-rex its ability to "balance its ten-tons." Its body "twitched even while the monster itself did not move." The reversal of the hunter to the hunted, Eckels's aplomb changing to cowardice, and, finally, the insignificance importance of the butterfly becoming monumental implies further this distortion.
With the monumental importance of the butterfly (hyperbole) comes the suggestion again of Biblical magnitude. Continuing the employment metaphor and parallelism, Bradbury explains this magnitude:
It fell to the floor, an equisite thing (metaphor), a small thing that could upset balances and knock down a line of small dominoes and then big dominoes and then gigantic dominoes, all the years across Time.
The only way to "take it back" as Eckels [this name suggests "echoes," a false return of sound] pleads is to remove him from Time. "He waited, shivering...There was a sound of thunder." Thus, the title itself becomes a metaphor for, perhaps, the revenge of an orderly God upon the evils of man.