All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.
The correct opinion according to the evidence from the Sunnah is that it is permissible to uncover the face of the dead and kiss him whether after or before the funeral prayer for him was performed, as it is confirmed that the Prophet kissed the face of ‘Uthmaan ibn Math’oon (after his death). [Al-Bukhari] It is also confirmed that Abu Bakr kissed the Prophet after his death.
However, some jurists are of the view that it is disliked to uncover the face of the dead person (after his death), because sickness and death may change the usual nice features of the person, therefore, if someone who does not know him sees him, he would think bad of him.
Nonetheless, the correct opinion which we adopt here in Islamweb, is the first opinion, but if the dead is a woman, then uncovering her face is restricted to her Mahrams if the one who uncovers her is a man because it is not permissible for a non-Mahram man to uncover her face.
Allaah Knows best.