What event causes Anders to imagine a cartoon bubble and what does it say?

Anders is looking at the mural on the domed ceiling of the bank. He describes the scene of Zeus and Europa, poking fun at the artist's interpretation of the classical Greek story. After describing the ludicrous way in which the artist had represented Zeus and Europa, as a cartoonish bull and cow, Anders imagines that if the bull were to have a cartoon bubble, it would say "Hubba hubba" (26).