Was she wearing a weird or noteworthy outfit? Does this person ask all the female tennis players to do this? Or was he just hitting on her or something?
She's the female equivalent of Grigor Dimitrov - both relatively attractive so the media hypes them to levels they almost certainly will never live up to. Part of that hyping involves constantly 'selling' them with getting her to twirl or him to dance and whatnot; gets the fanboys and girls onboard.