EWTN Catholic Q&A
The White cloth put on the pope's face
Question from Sr. Mary Terence on 04-13-2005:

I would like some clarification, I s it reference to one's Baptism? Thank You.

Answer by Matthew Bunson on 04-14-2005:

According to the liturgist in charge of the various ceremonies, yes, the veil placed over the face at burial is in part a reminder of baptism (according to what I have heard). Additionally, the white veil covers the pope's face to provide a proper appearance for the remains, especially in the event that at a later time the body is exhumed for examination (e.g., as part of the cause of canonization). Finally, the veil or covering is one way of treating the remians with the greatest possible respect.