The King sits facing forward on his throne, sword held upright. He wears blue, and butterflies are carved into the back of the throne. Behind him are a few trees and a cloudy sky. As the last card of the suit, this is where thinking has hardened into principle. The card describes someone who judges by standards rather than feelings, or that way of judging.
This kind of person sets the criteria before making the call. As a team lead, they do not go easy on a friend at review time. When something has to be weighed fairly — contracts, rules, dividing things up — their judgment can be trusted.
Reversed, the same principles push people away. Weighing only right and wrong, they lose sight of the other person's circumstances, and speaking from on high, they find nobody listening. The other direction is hiding behind principle: saying 'those are the rules' to avoid a judgment they would have to own.
The question this card asks is whether you would accept the standard you have set if you were on the other side of it. If yes, it is fair. If not, it may be your own convenience wearing the shape of a principle.
It is often read as 'authority' or 'the boss', but rank has nothing to do with it. The most junior person who settles a meeting with evidence is this King. The crown here is the weight of judgment, not power.
With Justice the judgment is very solid, and there is no reason to put the decision off. With the Queen of Cups it asks for the human side to be added to the rule — hold the standard, and hear the other person out to the end.