In his definition Walter Lippmann uses as a metaphor for culture?

Walter Lippmann did not use a specific metaphor for "culture" in his writings. He was a journalist, political commentator, and philosopher who wrote extensively on public opinion, democracy, and the role of the media. He is best known for his book *Public Opinion* (1922) which discussed how individuals form their opinions based on limited information and how this can lead to biases and misconceptions.

While he did not use a specific metaphor for culture, he often discussed the importance of shared experiences, values, and beliefs in shaping individual and collective behavior. He recognized that culture, as a complex system of meaning, influences the way people perceive the world and interact with each other.

If you're interested in finding a specific metaphor used by Walter Lippmann, it would be helpful to clarify which of his works you're referencing.