Bow down! Beyonce looks beyond beautiful on the cover of the September issue of Vogue, marking her third time gracing the pages of the famed fashion magazine. In the pic, shot by photographer Mario Testino, the "Flawless" singer is showing off her killer curves in a lavender lace dress with sequin floral embellishments. She adds some sass by swinging a sparkling purple blazer over her shoulder as she gives the camera a sultry stare. And in an homage to her "Drunk in Love" music video, Bey is rocking a wet 'do that takes sexy to whole new level. Another snapshot shows the songstress without underwear in a see-through netted black mesh dress that leaves little to the imagination. While the mag hasn't released any quotes from Bey yet, she is praised by several top designers in the cover story. "The word diva is used for so many female performers, and...