L. Frank Baum,
The art of decorating dry goods windows and interiors
(1900)
“ Under ordinary circumstances it is extremely difficult to photograph a window display, owing to reflections caused by dark objects in the display. These, acting in a similar manner to mercury on the back of a mirror, make the plate glass a strong reflector of objects outside the window. Frequently a photograph contains not only the window display, but trees, buildings, people, and even the camera itself, often to the total exclusion of important portions of the trim. If the glass is extra thick the reflections may be caused by a light colored display as well. ”
