
I found it difficult to choose one image too, but - since windows are the theme - here's a photo that I took in the Pentonville Road, London, in summer 2009. (You can see my reflection in the window.) I have no idea what '101% harmless' refers to but the materiality of the text struck me very forcefully. It's drawn into the dust on a plate glass window.
A few hours later: Since posting this, it's struck me that, of course, Walter Benjamin focuses on dust in the Arcades Project. This from Teresa Stoppani, 2007, 'Dust projects',
Journal of Architecture, 12/5, 543-557:
In Benjamin’s Passagen-Werk dust is associated with ideas of greyness, obsolescence and boredom. Dust blankets Paris like a heavy grey coat. It nests in the arcades and in the bourgeois interiors, materialising oblivion, stillness and decay. And yet, slow or fast, in both interiors and exteriors, dust measures the uncontrollable, penetrating that which is apparently ordered, organised, systematised. [my italics]And dust texts? Dust language even?