People
I have the easiest job in Hollywood, because I get paid to be me. What’s the role? A milkman? ‘Hey, I’m a milkman. Here’s your milk.’ ‘Cut. Print.’
— Christopher Walken

Behind the line May contain spoilers.
Our reading
An editorial interpretation.
This is a joke about acting: the speaker claims the job is easy because they're simply paid to be themselves. Then they imagine playing a milkman, just handing over milk, and a director instantly calling it done. The humour is in how effortless they make it sound.
Context reviewed