I don't think it's a new ability, Sarada was analyzing Mirai's moves to see what was the best strategy to strike her.Okay so:
1. I was right about last weeks episode about Boruto having no idea that Sarada possesses the sharingan :lol thus it her very own Addition to defeat Konohamaru.
2. The sharingan has a new ability! It can see the weaknesses now.
3. Sarada can curve her shuriken already