When you focus on a show window display with a normal camera, the reflection of the building behind it on the glass surface and your own image holding the camera will appear a bit blurred together. However, when photographed with a pinhole camera, both the display and the reflection of the glass surface are recorded in the same sharpness. Moreover, the image of myself, which was constantly moving while the picture was taken, has disappeared. This is why the image looks as if it were a double exposure rather than a single shot. By projecting the show window display (the real image) and the reflection of the glass surface (the imaginary image) in this way, without assigning superiority to either, it makes ambiguous not only the existence of the glass panel but also the positional relationships that should exist between the real and imaginary images, such as front and back, near and far, inside and outside, and so on.