Victoria Beckham, who stunned fans in a slinky black slip dress on Sunday as she shared details of her latest Victoria Beckham Beauty range.SEE: Victoria Beckham asks fans for advice following orchard mishap at Cotswolds estateTaking to Instagram, David Beckham's wife looked radiant as she posed for a selfie to showcase her new "Posh lipstick try-on experience," where shoppers can use the app to virtually try on products from her beauty range.WATCH: Victoria Beckham's utility-style skirt is