The Mystery of 62 Imlay

Yesterday’s interesting discussion about 160 Imlay Street prompted one reader to send in the photo of the building’s sibling to the north, 62 Imlay Street, along with this question:

Have you noticed that there is an entire floor of the other imlay building that is lit? someone installed a strange window (see photo) and there are definitely lights on 24 hours a day. are there still businesses in the second building? I always thought that it was vacant, as well.

So, how about it?

Update: We just got word that the entire building (all 235,000 square feet of it) is being marketed as a commercial rental by CB Richard Ellis.
160 Imlay Street: A Sacrificial Lamb? [Brownstoner] GMAP