When you are drunk and trying to get home, food is as valuable as gold. I can't tell you how bad it is to finally get home and realize that the only thing you have to eat is a Top Ramen seasoning packet. Then, since no stores are open, you have to wait six hours starving with a pounding headache before you can eat. That makes this photo all the more heartbreaking. This woman is obviously coming down from drinking heavily, and she has a delicious looking pie ready for her, but she couldn't keep it together long enough to keep the pizza safe.
It doesn't appear that any of the pizza is touching the floor, but you know how New York subway germs can be. They are super powered. I wouldn't be surprised if they'd already infested the pizza.