Desk

For almost a decade, my morning commute has taken me through the Roosevelt Island station, and during these rides I've noticed an office desk at the far end of the Coney Island bound platform.  This is the only desk (kind of school-issue, metal functional number) I've ever seen on a subway platform, & I wonder why it's there.  When I pass by, there's usually an officer slumped there, & he doesn't exactly seem busy. I get that a seat is useful if business is slow, but if it's so peaceful there, then why do they need security at all?  A couple of weeks back, I thought I'd get off the train to try & find out. 
As I got off the train & made my way down to the desk, I was already beginning to regret my decision, but it seemed silly to turn back.  As I got closer, however, the figure at the desk got up, as did a large and rather agitated German Shepherd.  Within about fifteen feet of the office set-up, the burly officer strode towards me, and with a traffic signal kind of raised hand gesture, told me sternly to "Stand back!" As he spoke, his evil companion strained at the leash and snarled. 
For some stupid reason, I still thought I'd give my question a shot, but it came out as a pretty bleating and pathetic affair.  "Just wondering ... kind of strange ... desk... platform.... only one ... security risk on island?" etc. It was not well received.  Offficer stared at me with a look of manic hostility & smiled.  "So, security.  It's a good thing. Yes?" He waited for an answer.  Dog grew restive.
More bleats from me.  "Yes .. security good thing ... still, desk seemed strange on platform, no?"
Officer silent.  Smiling less.  Dog bright eyed and excited.
I suddenly remember that I have a steak knife in my lunch bag, & decide that I should go.  Abandon idea of photo op, & bleat my last words. "Oh well, have to go, thanks ... er, desk still strange... er ... bye!"  Turn face, and retreat.

I still hope to get a picture of a manned desk, but for now this will have to do.  You can see that the desk has seen better days.

I still haven't solved the Costanza-esque mystery.  Why do the guys on duty here get to sit when others have to stand?  And what's the security issue here?  Island location?  Proximity to Queensborough Houses?  I would love to find out!