This position is also called "kneeling to the whip". It is a disciplinary position generally used, as the name suggests, for whipping a slave, in which the slave kneels, bowing her head to the ground/floor with her wrists crossed under her as though bound. In this position, the back and buttocks are exposed and easily accessible for lashing.
This position may also be used for other purposes, of course.
A slave presenting him/herself to confess to misbehavior should always assume the whipping position.