Blizzard revealed a new skin for D.Va and her along with new sprays and cosmetics as part of a Nano Cola Challenge. In order to get the sprays, an icon, and a skin, you'll need to win 9 games. The sprays show D.Va as she appears in the game and the new skin has her sporting a ponytail versus her usual hair down and pinned back.
There's also other sprays with the gremlin D.Va and the Nano Cola-drink. To get these, you need to link your Blizzard account to Twitch and watch up to 8 hours of streams being endorsed by Blizzard between August 28 to September 10. You can find the full list of streams here.