The players are listening to vital instructions before the proverbial starting gun sounds. Also, a tour of all of the games awaiting their players.
From the video description:
Start of [P]inburgh Pinball Tourn[a]ment. You see much more than 300 machines only reserved for the biggest tournament in the world. During FX-Replay Event at David Lawrence Convention Center in Pittsburgh.
Fun With Bonus is the home of the semi-coherent, misguided ramblings of professional and amateur pinball players.