I mentioned a while back that there is sometimes little distinction between public and private life here. This applies mostly, if not exclusively, to the locals, and by locals, I (and others) refer mainly to blue-collar workers of a slightly older generation, who have roots in Shanghai and whose living habits have not necessarily changed as the city around them does.
While I tend to be either intrigued or amused (or both) by it, this spillover of private into public has apparently caused other city dwellers some consternation, such as over the topic of wearing pajamas in public.

Let me assure you that while you probably wouldn't see it in any of the main tourist or shopping areas, people wearing their pajamas in public is not exactly an uncommon sight here. In my first couple weeks here, I saw a guy wearing what looked like quilted pajamas. They were marooon, top and bottom, with some beigeish pattern, and he was standing near a driveway. I wasn't quite sure what to make of it, and when I saw a different guy wearing exactly the same outfit in a nearby location a week or so later, I thought maybe it was a uniform. But other sightings since confirm (to my mind, at least) that nope, they were pajamas.

The pajama epidemic seems to be strongest around public parks and among the older generation, but is certainly not limited to those categories. I have also heard that it is primarily a Shanghai thing, although I'm not entirely clear on why the city is special in this respect.
Anyway, my favorites so far have been (a) this guy, whose wheelchair-bound patient/relative is nonetheless dressed "normally", and (b) a woman wearing Mickey Mouse pants that I'm sure Disney intended for home use. To be fair, she was wearing a non-pajamaesque top, so perhaps she doesn't actually consider those nightwear.