These "death masks" were mementos of the dead, though they also had other purposes like for creating portraits or for recording facial records of unknown corpses.
Here's a collection of death masks of the famous at Socyberty. To the left is Alfred Hitchcock:
Alfred Hitchcock dealt with death any number of times in his films - murder most horrid quite often - and in his death he retains a certain air of petulance.
He had a career that spanned six decades and most people are surprised to hear that he died as late as 1980. He directed over fifty feature films and is regarded by many as the most influential British film maker of all time.
He died of renal failure in California at the age of eighty. It is somewhat ironic that the film-maker who made generations of moviegoers wet themselves with fright should die of a kidney related illness.
http://socyberty.com/history/death-masks-of-the-famous/
From the Upcoming ueue, submitted by taliesyn30.