Panel 1: It would appear that we are being treated to a typical day at the day camp Liz got shipped off to because Elly doesn't want to raise her children. This is because we find Liz holding her nose as she tries to sit at the bottom of a lake only to fail because of her innate buoyancy.
Panel 2: As she resurfaces (and also as Chris Nichols clone Patrick looks on), we find her gasping for breath.
Panel 3: She explains to Patrick that no matter how hard she tries to sit at the bottom of the lake, she keeps floating to the top. His response is an extended insult. The part that occupies this panel is "I know."
Panel 4: The irritating payoff is "It's 'cause of all of the the air in your head!"
This does not please Liz because she hoped to escape asshole boys like Mike at day camp.
Summary: Her petty rivalry with this ape is not the payoff of this arc. The real problem is that Elly is really bad at telling children what to do. I'll explain why next Monday.