The main reason I chose it this week is because of the blur going off to the right of the letterbox. It's not the only Andrew Ross photo with some kind of movement blur in it. Because he uses long exposures in available light (exposures often run into minutes, sometimes hours), objects occasionally move while the shutter is open. This would usually be to do with old building things, like the floor moving as someone walks around, causing a broom to topple - something like that. The photographer has always noticed when these things have occurred, but on this occasion he has no idea what caused the blur.
This photograph keys into another interest of mine - the paranormal. Some years ago, for fun, some friends and I started a paranormal investigation team. Strange Occurrences was originally intended as a kind of elaborate, living, functional art installation; but it naturally became an operational unit! One of the only things we knew how to do early on was answer questions about photos that people sent in. Apparent paranormal phenomena captured on film or digital cameras, we found, could usually be explained rationally with a fairly high degree of certainty. Outside of photography, though, we knew very little.
In the photo above, something material has moved relative to the camera, causing a broad streak of light on the film. Another possibility is some kind of light leak in the camera or the sheet film holder, or mistake in film handling; but these seem far less likely possibilities. The exact cause of this blur remains a mystery. It is enticing, then, to believe that either Rita Angus or Tony Fomison, or even both of them, have made an appearance in the photo!