Target's New York pop-up shop for Zac Posen's collaboration line kicks off with a 24-hour party tomorrow at 11 p.m. (481 Eighth Avenue, at 34th Street), more than a week before the line hits stores, so New York fashion director Harriett Mays Powell stopped by the designer's downtown studio for a preview. "It's a collection that's about the best summer of a woman's life," the designer explained, while adjusting certain pieces, showing how they can be worn several different ways. Watch the video for more.