Victoria Beckham marked the opening of the Tokyo Olympics on Friday by reminding fans of her starring role in the London 2012 closing ceremony – and of her thigh-skimming outfit!The fashion designer delighted her followers with a throwback snap of herself wearing her now-iconic strapless black mini dress with billowing train by Giles Deacon.MORE: Victoria Beckham reveals the fashion trend that's going to go wildDescribing the night as "one of the proudest Spice Girls moments", Victoria can be