Answer: It stresses the tension of the battle, showing that the soldiers were trapped.
Step-by-step explanation:
Lord Tennyson often uses a figure of speech called anaphora in “The Charge of the Light Brigade.” This figure of speech is characterized by the repetition of the same word at the beginning of a number of lines. In this case, word "cannon" is repeated three times in a row: “Cannon to right of them / Cannon to left of them / Cannon in front of them.” The repetition suggests that the conflict between the two sides will inevitably happen. It also describes the unfavorable situation in which the soldiers found themselves - just as the readers encounter the word "cannon" at the beginning of each line, the soldiers see the cannon wherever they turn.