Mom headed instinctively to Rockerfeller Plaza where I took the requisite tourist photos. One thing I appreciate about my Mom is that she had annotated her map of Manhattan with the position of every Anthropologie (and a few other shops which we don't agree upon, but nonetheless). The Anthro off Rockerfeller Plaza is huge and included an art installation.
The shopgirl was able to direct us to the nearest Post Office, which, of course, was closed. But, it did have a sign in the window with the address of a Post Office which would be open late. So, we continued our walk.
I successfully mailed my packages for an unbelievably low price.* In another coincidence, next to the Post Office was one of the restaurants recommended by my mother's friend, while we waited at Pearson.
This synagogue was really beautiful, and I liked that you can see the Chrysler Building in the distance.
My mother was far too amused by "Eleanor's Building" with the "She Who Must Be Obeyed" sign.
I spotted these sculptures as we approached the Park and said, "I want to go look at the animal heads." I was glad I did. These were "Circle of Animals/Zodiac Heads" (bronze, 2010, each weighing ~800 lbs., inspired by the "fabled fountain clock of Yuanming Yuan, an 18th century imperial retreat outside Beijing") by (the still detained) Chinese artist Ai Weiwei. One sign read "Free Wei Wei". The sculptures were quite spectacular.
We got back on the subway to return to our hotel for the night. I liked how this subway map was annotated ('Dystopia', 'Human Alter', 'The Money Tree', 'Slave Factory', 'MOB','4 Hours Sleep', etc.).
EDIT: Apparently it's privatized, though it has a deficit.