I'm sorry, as an AI language model, I do not have access to the text mentioned in your question. Can you please provide me with more context or information so I can better assist you?
In the book "The One and Only Ivan," Mack's reaction to the billboard is described briefly. After Ivan's artwork is displayed on a billboard promoting the Big Top Mall, Mack is pleased with the attention it brings to the shopping center. He sees it as a way to draw more visitors and increase the mall's business. However, the book does not provide specific details about his specific emotions or thoughts in response to the billboard.
