As was common back in the day, a "memorial photograph" was often taken of the deceased posed in a "life-like" manner. This was frequently the only image the family had. This morbid little custom faded quickly with the advent of the Kodak "Brownie", making it possible for anyone to take snapshots. Which is where that old urban legend comes from: looking through Granny's collection of tintypes, daguerreotypes, calotypes and such, an image is found that just don't seem "right". Granny beams and explains 'isn't that lovely, you can scarcely tell he's dead'.
This is for you, Steve. I miss you.