As far as Islamic Shari`ah is concerned, potential spouses are not only permitted but also encouraged to see and look at each other before engagement. When Al-Mughirah ibn Shu`bah (may Allah be pleased with him) made a proposal of marriage to a woman, the Prophet (peace and blessings be upon him) asked him, “Have you seen her?” He said, “No.” The Prophet said to him, “Go and look at her, for it is more likely to engender love between the two of you” (Ahmad).
On the basis of this and other similar hadiths, the jurists have said that it is allowed for a man and a woman who are considering to marry each other to see and meet each other in the presence of their adult relatives. The meetings should be supervised and with proper Islamic dress and etiquette. Potential spouses even after engagement are considered foreigners (i.e. not officially married yet), and therefore the rulings of non-mahram people of the opposite sex apply to them until they get married.
Sheikh Ahmad Kutty, a senior lecturer and Islamic scholar at the Islamic Institute of Toronto, Ontario, Canada, states, Islam allows potential spouses to see each other and speak in an formal manner in order to get to know each other as long it is done within the acceptable limits for the purpose of determining suitability for marriage. In such a case, it is not only considered as permissible to do so, but rather as being highly recommended. The Prophet (peace and blessings be upon him) said to people who are considering marriage, “Look at each other, for it may help you in fostering your relationship” (An-Nasa’i, Ibn Majah, and At-Timidhi).
Now coming to the matterr of what a man is allowed to see from his prospective spouse, the acceptable view of scholars is that he is not allowed to see anything except her face and hands or feet. There is no clear evidence to permit him to see her hair or leg. Since there is nothing to clearly permit it, there is no justification in allowing him to see her hair or legs. The general rule of prohibition stands fast unless there is a clear text, and since there is no such text, it is ruled as impermissible.