If you step outside Sloane Square tube station, and immediately look to your left, you see this:
This is one of those phenomena which doesn’t photo very informatively. By which I mean that if you are there, it is far easier to see what is going on. So let me now tell you what is going on. This is the inside of a new building, but covered up, while they’re completing the building, with a sheet. This sheet has another building painted on it. And there is light coming at the sheet from behind. When what is behind the sheet completely blocks out light, we see the picture on the surface of the sheet. But when light comes at us from beyond the sheet, the picture on the sheet is overwhelmed, and we observe either light, or any shapes (in this case steel structure and scaffolding) in silhouette.
What I like about this effect is both its temorariness, and the fact that it ends up looking so much more interesting that it was intended to look. The idea was that we would only see the picture on the sheet. What we actually see is a whole lot more diverting.
Here is another photo I took of the same thing, this time including a bit more context:
It’s a little more clear, in that photo, that there is a picture on a surface as well as all kinds of excitements behind it, on account of the sheet consisting of surfaces at an angle to one another.
Best of all, you can now see that one of the excitements behind the sheet – to be more exact, one of the structures behind the sheet – is a crane.