When Mr. Grouper says It's time for lunch, The guppies go into a library. However, most libraries do not allow people to eat inside.
When Mr. Grouper says "It's time for lunch", Goby is seen holding his green lunch box and Nonny is holding his orange lunch box. But after the giant bubble pops and shows Molly, Goby, and Nonny in a library, Goby and Nonny's lunch boxes are switched. So one would assume that if they hadn't switched, Goby would've gotten the lunch joke instead.
This is the first lunchtime segment in season 2 that Oona is not involved in.