How does «person» really feel?
Where an immediate question could give us the impression a person wants to give, this question pierces the mask. It might not reveal what lie a person has told, but it should reveal hens intent to deceive or mislead. It should reveal when someone means you harm, or when someone genuinely wants to help you. If hen has something on hens mind, this question won’t necessarily tell us what weighs on hen, but it will tell us that hen has something on hens mind for us to find out about.