Thanks for the pictures!
Grand Central Station looks nice on picture and TV! actually, it's quite hot and stuffy in the summer, or the whole NYC subway tunnel, and some of the trains don't have air conditioner, it can get quite stuffy. Remember one of the Seinfeld episodes, where Elain got stuck on one of a "dead" trains, and it didn't move anywhere, she felt "suffocated" and she wanted to scream MOVE outloud. I think I could relate to that experience.