Chris

You could be generous and say he probably isn’t miming a hand job, but it’s pretty clear he’s jokingly fellating the thing afterwards. Especially in the context of the whole incident, in which he raged for 4-5 minutes because the mic stand was broken and he had to hold the mic in his tiny hands.

I suspect he jiggled the mic stand to emphasise its brokenness and it occurred to him at that point that he could make a sex joke out of it, hence the head-bobbing that followed.