What is the significance of the picture of lemmings jumping off a cliff in relation to the concept of mass hysteria and groupthink?

The picture of lemmings jumping off a cliff is often used to symbolize the concept of mass hysteria and groupthink. It represents how individuals in a group may blindly follow others without questioning or thinking critically, leading to irrational and harmful behavior. This image serves as a cautionary tale about the dangers of conformity and the importance of independent thinking.