Is it permissible for a woman to uncover her face for a man who asks her to do so, in order for his heart to be convinced and for him to propose to her?

It is permissible for a woman to uncover her face for a suitor who wishes to propose to her, so that he may look at her, provided there is no private seclusion (khalwa). This is because looking before the proposal is permissible for one who is determined to propose and expects a positive response.