The Joker is a Trickster figure. He reveal the shadow of anyone in front of him.
In mythology, he his associated with Hermes, the god of commerce, frontiers and the god of thiefs…
He’s encounter with Batman and the gang of mafioso can be resumed by:
“Be free of your rewarding system or you will be trap in that system”
That’s why when he steal the money, he burned it…
He act for the free expression of acting…
But he confront us (as person and society) to our own shadow that can burn us when we act too far from our own truth…
Maybe that’s why we are so fascinated and so anxious about the Trikster Clown at the White house too…