What do you mean? She's underwater. As master of the ocean's waves, she sometimes likes to hover overhead to state her importance. Plus, she didn't like the way you were ogling her.
I think she was just changing a burnt out bulb in that plant/streetlamp thingamawhatsit she's standing on.
I have not seen her hovering yet but really? is this anything new? Its been a while but at one point of you went to Central City.. that would be the old one without giant star fish attacking..... You could find yourself staring at the Flash and his twin brother Flash 2. Standing side by side and ready to say hi and give you a mission. Just another in a long line of "oh hey look what he/she is doing today! Wow that looks strange dpoesn't it? " visuals we have come to know and love in game. Now I did a quick search and while i never encountered this .... Apparently it could get even worse... So basically we have Barry as Flash, Wally as Flash, and Bart, Impulse, Allen all standing by to hand out missions LOL
She's up there because a villain came over to check how she was doing, and her skin crawled up the wall Cereally, she is unbelievably rude to villain characters, and after they helped save her scaled arze
Technically, she's not floating, she is standing, butt the way the game 'works' with objects she is standing on the lamppost (at least this is better than standing at a 45 degree angle on a curb )