It is important to realise the drama that this chapter contains. As Brother Leon takes the daily roll call of how many boxes of chocolates have been sold, everybody, Brother Leon included, is full of tension now that Jerry's Assignment is over and he can take and sell the chocolates. Thus it is that everyone expects, with relief, Jerry to start selling chocolates like everyone else. When he chooses to continue to defy the system, therefore, the shock is immense. The quote you have identified comes straight after Jerry shouts out his defiant "No!" once more, but this time without any overt reason behind it. The descriptive detail of the quote you have identified, which compares Goober's eyes to a lens of a television camera, aptly describes how his eyes would have zoomed in to Jerry's face to focus on his facial expression. The magnitude of this event is highlighted by the final paragraph of this chapter:
Cities fell. Earth opened. Planets tilted. Stars plummeted. And the awful silence.