Post-mortem photography (also known as memorial portraiture or memento mori) is the practice of photographing the recently deceased. The practice peaked in popularity 19th century and died out as "snapshot" photography became more commonplace, although a few examples of formal memorial portraits were still being produced well into the 20th century.
     The fact is, postmortem photographs like this were taken more than any other kind of photograph in the Victorian era — especially in the U.S. — and in many cases these carefully-arranged, meticulously staged pictures were the only ones ever taken of their subjects. From Stanley Burns’ book Sleeping Beauty: Memorial Photography in America:
   



These photographs served less as a reminder of mortality than as a keepsake to remember the deceased. This was especially common with infants and young children; Victorian era childhood mortality rates were extremely high, and a post-mortem photograph might have been the only image of the child the family ever had. The later invention of the carte de visite, which allowed multiple prints to be made from a single negative, meant that copies of the image could be mailed to relatives.