This image, and others, can be found at Mental Floss under the heading of “Only the Creepiest Photos Ever Taken.”
The post includes the following quote from Sleeping Beauty: Memorial Photography in America by Stanley Burns.
These photographs were a common aspect of American culture, a part of the mourning and memorialization process. Surviving families were proud of these images and hung them in their homes, sent copies to friends and relatives, wore them as lockets or carried them as pocket mirrors. Nineteenth-century Americans knew how to respond to these images. Today there is no culturally normative response to postmortem photographs.