You're looking at the raw space that's about to become Google's new Chelsea Googleplex. Curbed provides the photo and details about the "mad square footage" of the new digs:

"The space stretches the entire square block from 15th St to 16th St, from 8th Ave. to 9th. It used to be occupied by Prudential Financial Services. You could probably host quite a sizeable party in there. Looks like they have a lot of work to do! I actually saw someone walking around in there today, so I think they are starting to build it out. I actually had to run out of there so I wouldn't get questioned. They take security pretty seriously in this building. Several weeks ago I was snooping around as well and there wasn't a soul to be seen."