Jake Gyllenhaal famously lost 30 pounds for the role and improvised many of Lou’s unhinged monologues. Watching these moments in a environment allows you to see the bags under his eyes, the unblinking stare, and the smile that never reaches his eyes.
The movie explores themes of ambition, morality, and the voyeuristic nature of modern society. As Lou's obsession with capturing footage grows, so does his ruthlessness and disregard for human life. The film presents a critique of modern media's focus on sensationalism and the lengths people will go to achieve success.
He found his shot: a wounded witness slumped against a brick wall, the light hitting the crimson stain on their shirt just right. Most people would see a victim; Lou saw "high-definition fear." He adjusted the focus, the mechanical whir of the lens the only sound in his ears. He didn't help. He didn't call out. He just watched through the glass, waiting for the perfect frame of misery to sell to the morning news.