The princess knows what is behind each door and has to decide which door she wants her lover to open. "she knew in which of the two rooms that lay behind those doors, stood the cage of the tiger, with its open front, and in which waited the lady." page 302.
After the princess gestures to the door that she wants him to open he opens the door. "She had known she would be asked, she had decided what she would answer, and without the slightest hesitation, she had moved her hand to the right." page 304.
The princess told her lover to go to the door with the tiger because she would have been jealous if she would have chose the door with the lady and she would rather have him dead than him be with another woman. "Would it not be better for him to die at once, and go wait for her in the blessed regions of semi barbaric futurity?" page 304.