Obviously someone Pete told him he'd better start throwing his weight around. Being MacGyver, he looked around the place where he happened to be at the time, and found a pole that would serve marvelously as the object to act as a central axis for said weight, and improvised a manner of doing that, using a chain and another bit of steel rod that was lying around. Always improvising and inventing, that's our Mac!

Regardless, he certainly seems to be doing it with a will, isn't he? Not to mention a cheerful grin.