The hardest part in this type of collection is looking for the clues. Some are obvious such as the family gathered around the coffin or loved one as they appear to be taking a nap on a sofa. While this seems creepy to us today we have to remember the times. In the second half of the 19th century and first part of the 20th century when this was widely practiced it often was the only time they could get a photo of the whole family together. The middle class was the largest group to take part in this custom so don't always assume only the wealthy took part as many people do.
The primary reason that it took place was because the mortality of young children was so high it was sometimes the only chance the relatives living elsewhere had to see them. It also may of been the only opportunity to get a photo of the person. Grieving also came into play here it was felt that by having a last photo of the deceased could quicken the grieving process and pay tribute to them.