Let me qualify that bit about only one policeman in our area. There were plenty around only a few yards away by the cement blocks, and some in a stair-well behind us -- but it was not like earlier at the park or at some other rallies when the horses, swats, and motorcycles surrounded us. The crowd, yesterday, was very peaceful (for the most part) mostly women, and there was never the threat that we felt at other times. The lone officer a few feet from us never showed concern, and in fact was smiling almost the whole time.
Probably undercovers also, as you say, and maybe even dressed in pink! LOL!
It got a little more *lively* after you had to leave for your train, exit. There were a few more "waves" of marchers that came through. I think it was 6 or 6:30pm before we finally packed up and left our corner.
I'm working on uploading my pictures now... I hope you got some good ones. I didn't get too many this time. (too busy with other stuff)