The characters literally combine to mean “embroidered flower pillow.” The idiomatic meaning arises from the universally understood contrast between the decorative, valuable exterior (the embroidery) and the cheap, simple, and hidden interior (the stuffing).
The term 绣花枕头 reflects a deep-seated pragmatism in Chinese culture. While “face” (面子, miànzi) and appearance are important, there is a strong cultural belief that true worth comes from substance, skill, and practical ability (本事, běnshì). This idiom serves as a cultural check against valuing superficiality too highly. In Western culture, a similar concept is “all sizzle and no steak” or “window dressing.” However, 绣花枕头 is more personal and visceral. “Window dressing” often applies to business or marketing, a deliberate attempt to mislead. 绣花枕头 can be used in the same way, but it's also frequently used to describe a person's inherent character—someone who is naturally attractive but lacks intelligence, skill, or depth. It carries a tone of disappointment, as if something promising turned out to be hollow.
绣花枕头 is a common, informal term used in everyday conversation. It's almost always derogatory and carries a strong negative connotation.
It is considered informal and is not suitable for formal reports or very polite company. It's a blunt and critical assessment.