What do you think of a coworker who seems to get special treatment from the boss?

My boss doesn't ask me to do any hard tasks. All I do all day is walk with a machine so the operator has another set of eyes. My coworkers do heavy manual labor all day, everyday. I get all of the easy work like the walking, sweeping and doing little tasks that need to get done. My coworkers don't seem to like it, but I don't care. I'm thee to work and do what my boss asks me to do.