As Zach and Joey are talking, Zach is holding Jelly and bread. The camera goes to Joey and when it returns to Zach the products are out of his hands.
When Joey confronts Kenny about his attitude saying, "The only reason you're acting like this is because no one told you you can't!" In the shot Joey is saying this Kenny is holding his bowl with his left hand. In the next shot he is holding it in his right hand.