Is it permissible for a woman who wears a hijab to appear without it before her fiancé after they have agreed on the details of the marriage and announced the engagement, but before the marriage contract has been concluded?

As long as the marriage contract has not been formalized, the suitor remains a stranger to his fiancée. It is not permissible for her to uncover herself in front of him, nor for him to be in seclusion with her. What was mentioned about agreeing upon the down payment and deferred payment, and the presence of male family members, does not constitute a contract. Rather, it is a promise of marriage. The valid contract is that in which offer and acceptance have been made. The pillars of marriage are: the woman's guardian, the presence of witnesses, and a specified dowry, in a manner that all perceive as a binding contract permitting the man to enjoy intimacy.