Joker is a person employed to tell jokes and provide general entertainment. The Joker is also special card found in modern decks of playing cards; there are only two of them in a pack!
The Joker is taking advantage of his license to mock and speak freely to dispense frank observations and highlight the folly of others.
Making fun and mocking other can be fun but also dangerous… don't overdo it! Laugh out loud, have fun!!