Having looked up the relevant part, let me transcribe it for you:
> "One of the first things that struck Jen and me as we entered the GDS office on an upper floor of an old office building high above a busy London street was a large sheet of butcher paper covering the picture window in the lobby. In the paper was a small cutout through which you could see the people on the street below. The cutout had a large arrow pointing to it, labeled "Users", reminding everyone when they walked in just whom the unit was meant to serve."
I found it really drove home the service's users-first approach. Following that anecdote he elaborates on the service's "10 commandments" (the 10 GDS Design Principles). They're also quite interesting, but I'm sure a search engine lookup can help you there. I really recommend the book if you want an optimist's outlook on the future of technology, government and economy.