"there is more to {sb/sth} than (what|) meets the eye" 的定义和意义

What is the origin of the idiom "there is more to someone or something than meets the eye" and when to use it?

The idiom "there is more to someone or something than meets the eye" originated from the idea that appearances can be deceiving and that a superficial observation or understanding does not capture the full depth or complexity of a person or thing. It suggests that there are hidden qualities, characteristics, or aspects that are not immediately apparent or easily discernible. The phrase emphasizes the need to look beyond initial impressions and delve deeper to truly understand the true nature or value of someone or something.