O's 10th anniversary issue had been in the works for a year. After all that planning—including collaborations with designers Isaac Mizrahi and Badgley Mischka on Oprah's gowns—hopes for a dazzling cover were very high. "I wanted Oprah's look to radiate celebration," says O creative director Adam Glassman. "The gowns were exquisite—but until Oprah's in front of the camera and fully styled, you never quite know how a garment will work out." Once Oprah arrived in oversize sunglasses, and Lady Gaga began blasting through the speakers, the energy spiked with a flurry of quick touch-ups and tweaks.