The 4 at 3

Please give me any feedback that comes to mind, particularly with

regard to recommendations for image manipulation (contrast, tonality,

etc).

Nice pic, but that's not the 4 train. That's an R46, a car that's too wide to fit on any numbered line on the NYC Subway. The cars on the 4 train have longitudinal seating, not transverse seating like in this picture.

Great candid shot, 6/6

This worked due to the b&w. Nice.

I think this image is a bit contrasty, and lacks focus. Where should my eye be looking?

I love it, particularly the clutter. So many little stories, all seamingly isolated with hand-rails. Well done, an excellent photo