In a time when some brokers question the value of brick-and-mortar offices as technology allows their agents to work in the "cloud,"  one brokerage has decided to go big, and build a real estate retail space at its office. Zilbert International Realty, a luxury boutique real estate firm in the South Beach neighborhood of Miami Beach, Fla., has flipped the new conventional wisdom on its head by building a 4,000-square-foot flagship office in a tony South Beach retail center. The brokerage, which primarily represents condo buyers and sellers, is looking to turn real estate into a retail experience. Walking into Zilbert International Realty's new 1-year-old office is open to the public from 10 a.m. to 5 p.m., seven days a week. Visitors step into a simple, streamlined space with rec...