Paul was writing partly to slaves, which makes this verse land harder than it does in a modern office. Whatever you do, work at it with your whole being, as for the Lord and not for men.
He does not promise the work will become interesting. He does not suggest they will be recognized. He changes one thing only, which is who the work is actually addressed to.
That single move rearranges a great deal. If the audience is people, then unnoticed work is wasted work, and resentment is only a matter of time. If the audience is God, the arithmetic changes completely. Nothing is unwitnessed.
With your whole being is the demanding part. Not adequately, not enough to avoid trouble. Fully, on something nobody is checking.
Most of what you do today will go unremarked. That is not a reason to do it carelessly. It is the exact circumstance this verse was written for.
