zzz - your pic didn't show up for me, although I can click on it. Anyway, in case somebody doesn't click through, it shows a bunch of people on a crowded metro train: several of them reading.
And what does that make me think of? Well, totally unrelated to the themes of mass transit or reading or anything - I just noticed how much black clothing there was in your pic. Those black legs right in front, with black shoes, black socks, and a patent leather black bag... and then I noticed all the black jackets, many of them leather...