Maybe he's a "tweeker", somebody who's job is to tweek the machine when something looks like it might start to go awry. If nothing needs tweeking he has nothing to do but keep watch.
My previous wife worked in a factory making shipping tags (in the days when they used such things), pretty much all of the machine operators constantly tweeked the machines which saved the maintenance crews having to shut down lines to correct the catastrophes which would have otherwise occurred.
Or he might just be a lazy bastard.
