I think it takes place every Saturday morning to afternoon, vintage shopping while having a great view at the Manhattan skyline from the East River State park. You will find lots of vintage shops and warehouses around this area of Williamsburg.
I live above TriBeCa and take walks into and around this area often. It's quiet, usually on the emptier side, and hosts a few gems of restaurants including Tiny's, Takahachi, and Odeon - all on the same block of West Broadway.
Cobble Hill Cinemas is a cozy little neighborhood theatre. It has all the charm Brooklyn has to offer, screening new releases as well as selected independent films.