There are rather reassuring:
It's an emergency telephone. These have been popping up in the subway, and it's a capital improvement of which I approve.
There have been emergency telephones in the subway for a long time, but they were actual phone receivers that you had to pick up---consequently they were often ripped out of the wall. Probably people used to them try to order pizza. Then they had push-button emergency intercoms, but they were hard to find. They didn't have that calming blue cop light making them stand out.
This has an added benefit in that it has two buttons, one for emergency calls and one for information. So you could push the emergency line if you lost a child, and the information line if you're lost yourself. The emergency line could report a drunk fallen on the tracks or a suspicious package left on a train; the information line could help you get tickets to Phantom. (Not really.)
You might think that these days everyone has a cell phone so no one needs such a thing, but even if that were true, there are advantages. If you are in danger and you push the button, they know what station you are calling from instantly. (So don't get the idea that you can use it to pull jolly pranks on the 911 dispatcher. Remember, there are cameras too.) It's like a harmless, immobile Robocop.
Looks well-built. Probably really hard to rip out of the wall. And you don't have to hold a receiver up to your face, which was always the worst thing about public phones. "Hello, 911? I want to report Ebola. On my face. From this phone."