Play Writer and Director:
King's love, generosity and good are not good enough to win over the heart of the Donkey Skin. They can only show it the path of self-knowledge and quest for identity. That path is filled with difficult temptations, challenges and great suffering.
On that path, the Donkey skin discovers its own good traits that will warm down Prince's cold heart.
The King's love leads to the chain of noble events. Those events result in happiness.
Love can't be bought or won by force. What is great about love, is that no matter how unfortunate and impossible it seems, in the end it always brings love.