The word 丢脸 is formed through a vivid conceptual metaphor where "face" (脸) represents one's social dignity, honor, or prestige. The character 丢, meaning "to lose" or "to throw away", is combined with it to create the immediate mental image of literally misplacing or having one's respectable public image stripped away. This visually encapsulates the feeling of public shame or humiliation, as if a person's social standing has been carelessly lost or discarded for all to see.