I love to see stuff like this on the train; I think it's so funny. 
The subway provides a lot of entertainment. There was one time when
Tom and I took the train to 1st Avenue to go to a party at
Joshua Suzanne's. I was at one end of the car and Tom was at the other. I was tired, leaning against the doors, and there was a couple across from me. I had my eyes closed but I heard the woman say,
"That is
so gross."
Her boyfriend said, "That's New York for you."
I didn't see what it was, but soon after I heard
excitement at the other end of the train. I don't want to say, "screaming", and not "yelling", but something in between. Something kind of fun.
I couldn't tell what was causing the far end of the crowded car to move this way and that, everyone looking at the same spot at the same time. Some people would jump away from the wall; the seated passengers would raise their legs off the ground in quick succession .. . the L train Rockettes.
Then the wave came to me as I stood alone against the doors. I looked down and a rat darted behind my boots, into the corner of the train. Everyone looked expectantly toward my corner.
Everyone was smiling.