Two examples of figurative language in the passage are "her stomach dropped like a free-falling elevator" and "her voice an impostor as it boomed through the microphone."
The first example, "her stomach dropped like a free-falling elevator," uses a simile to compare the feeling of anxiety or fear to the sensation of an elevator plummeting, emphasizing the intensity of Melanie's emotions as she prepares to speak in front of an audience.
The second example, "her voice an impostor as it boomed through the microphone," employs personification by suggesting that Melanie's voice is pretending to be someone else's, highlighting her discomfort and the disconnect she feels between her true self and the authoritative voice that is projecting from the microphone.