Tbh the suspected USO dresses (well from what I usually see Masha wearing) you can always tell from the back. The racer-back is such a Masha shape.
Usually Serena has round/scoop neck silhouettes. But the colour and design is so daring that it's leading me to believe that Masha is too commercially-minded to design such a thing
and then I'm balancing the pretty fan skirt and thinking of Masha - but then the last time she wore something truly girly was last years USO, with the booby area up top which is making me think of Serena
The graffiti dress looks like something that Serena would wear because she's very experimental with prints, and lets not forget that USO is her turf and she likes to reference culture. Remember that African inspired headband at AO this year? Who knows, it's all speculation at the minute but with the beautiful design of the day dress how can it not be an outfit for a top player?
Maybe they decided to show Maria's day dress and Serena's night dress so as not to reveal everything (*here's hoping*)