As SL Green is developing Midtown’s largest commercial property at One Vanderbilt across the street from Grand Central Terminal, the company is also building the neighborhood’s smallest ground-up project at 719 Seventh Avenue, just one block north of Times Square’s northern terminus. Despite its diminutive four-story size, the retail building will assert itself via a 150-foot-tall, 5,000-square-foot array of digital billboards. On-site demolition is complete, and excavation is well underway. Pavarini McGovern LLC is listed as the construction manager.