I had completely forgotten about this fence. We saw it from Hyde Park, London while there last November. Isn't it great! I believe it was on top of a scaffold walkway, the building behind it was clearly undergoing renovations.
The pencils had different words on them like, 'East is East, and West is West', 'A Creaking Door Hangs Longest', 'Nice one, Cyril' and 'Art is Long and Life is Short'.