Thanks Mustafa and despite its age it still works perfectly, requires no batteries and most important of all when you press the shutter it takes the picture without delay.
I keep coming back to this, Clive, and in my head is one word: rectangles. There are so many of them, and the echo of that shape reverberates loudly. I'm glad I found out what attracted me to this picture; for a while I couldn't pinpoint it. And the puppy, of course...