George doesn't accuse Larry of dropping another hat in the last panel for the same reason his dialogue balloon is so awkwardly placed: I didn't want to cover up Rhea any more than necessary.

As for why the elaborate costume, I wanted Rhea's cat form to come with an outfit change, and I didn't want it to just be a generic one piece swimsuit with a collar or something (which I've admittedly had characters wear in the past.

So I decided on a fancy, possibly "magical girl" outfit with gloves and boots that are paw-like. Assuming it is a magical girl outfit, you can bet those paws can generate projectile slicing attacks or some nonsense.