How did the princess indicate to her lover the door of her choice?

"The Lady or the Tiger" by Frank Stockton is one of the most famous short stories of all time. Its effectiveness lies not in providing a solution, but in posing a dilemma.
In this story, set in an ancient kingdom, a semi-barbaric king has a unique method of justice. For a crime sufficiently severe, he has the accused placed in an arena in which there are two doors. Behind one is a horrible ravenous tiger that will tear him to shreds and devour him; behind the other is a lovely maiden to whom he will be wed.
When a common courtier commits the unpardonable offense of falling in love with the princess, he is thrown into prison and then taken to the arena to make his choice. When he arrives, he bows to the king but looks to his lover, the princess, for guidance. He trusts that she has learned the secret of the doors and will show him the one he must open. This is how the story says she indicates her choice:

Her right arm lay on the cushioned parapet before her. She raised her hand, and made a slight, quick movement towards the right. No one but her lover saw her.

So, she indicates through a movement of her hand that the courtier should open the right door. Then the story questions what she would have chosen for him. She would hate to see him torn apart by the tiger, but she would also hate to see him in the arms of another woman. Which fate does she decide for him? The story never tells. It is up for each reader to wonder about the answer to this question.