Recent Roosevelt Island Condo Sale at Hudson/Related Riverwalk Building

According to Property Shark, apartment 4G, a 1 bedroom, 674 sq. ft. 1 bedroom apartment at Riverwalk 455 Main Street sold on August 20, for $589,000. NY Times Real Estate section lists Roosevelt Island condos for sale or rent here, Streeteasy lists here and Craiglist here.
Image is from The Architetect's Newspaper.