EVG reader Doug, who shared these photos, noted the building's "High Line East vibes" ...
According to published reports this past fall, the building with floor-to-ceiling glass and private terraces has its first two tenants: Newrez, a mortgage lending and service firm, and Bain Capital Ventures.
No. 799 was the former home of the historic St. Denis building (not landmarked, unfortunately), which opened as a hotel in 1853. Normandy Real Estate Partners bought the property for somewhere in the $100 million ballpark back in 2016... and tore it down.
Our post on No. 799 from January 2020 has a little more background about the project and the concerns over this out-of-scale construction along this corridor.