Definition & Meaning of "warts and all"

What is the origin of the idiom "warts and all" and when to use it?

The idiom "warts and all" is often attributed to the English soldier and statesman Oliver Cromwell. According to legend, when Cromwell sat for a portrait, he instructed the artist to paint him accurately, "warts and all," without idealizing or flattering his appearance. Whether this story is entirely true or not, the phrase has become associated with the idea of depicting someone or something as they truly are, flaws and all. This idiomatic phrase is used to indicate an unvarnished or unembellished representation of someone or something, without trying to hide imperfections or weaknesses.