A Mirror reflects a portrait of the artist who made it, or a window, through which one might better know the world.

In the summer of 1835 William Henry Fox Talbot experimented with various chemicals to develop paper coatings suitable for use in a camera. He placed small wooden cameras that his wife called “mousetraps” all over his estate. The earliest surviving paper negative dates from August 1835, a small recording of the bay window of Lacock Abbey (left). In 1978, the German photographer Floris Neusüss visited Lacock Abbey to make photograms of the same window. He returned again in 2010 for the Shadow Catchers exhibition at the V&A to create a life-sized version of Talbot’s window.

The idea of photographs functioning like windows makes total sense. Like the camera viewfinder, windows frame our view of the world. We see through them and light enters the window so that we can see beyond. Photographs present us with a view of something.
However, it might also be possible to think of photographs as mirrors, reflecting our particular view of the world, one we have shaped with our personalities, our subconscious motivations, so that it represents how our minds work as well as our eyes. The photograph’s glossy surface reflects as much as it frames. Of course, some photographs might be both mirrors and windows.

“The two creative motives that have been contrasted here are not discrete. Ultimately each of the pictures in this book is part of a single, complex, plastic tradition. Since the early days of that tradition, an interior debate has contested issues parallel to those illustrated here. The prejudices and inclinations expressed by the pictures in this book suggest positions that are familiar from older disputes. In terms of the best photography of a half-century ago, one might say that Alfred Stieglitz is the patron of the first half of this book and Eugène Atget of the second. In either case, what artist could want a more distinguished sponsor? The distance between them is to be measured not in terms of the relative force or originality of their work, but in terms of their conceptions of what a photograph is: is it a mirror, reflecting a portrait of the artist who made it, or a window, through which one might better know the world?” 
— John Szarkowski, 1978.