With “For My Best Beloved Sister Mia: An Album of Photographs by Julia Margaret Cameron,” the Pittsburgh Frick organized this nineteenth-century photographer’s fecund practice around the contents of a mammoth tome containing works that the artist dedicated to her sister. The collection of seventy images includes photographs by Oscar Rejlander and Lewis Carroll and forty-seven taken by Cameron herself.

While the actual album occupied a vitrine at the center of the main gallery, its heft and inaccessibility intimating entombment, the individual photographs, by contrast, unfolded the filaments of