" has whittled the contestants down to a small group of designers, and now, it's time to shake up the weekly runway format. For this week's challenge (Tues., May 1, 10 p.m. ET on NBC), the remaining designers are focusing on their personal brands and creating campaigns for their collections. The mentors -- Nicole Richie
, Jessica Simpson
and John Varvatos
-- will give the designers guidance and insight into what makes a ...