Drill Sergeant Asuka for the win! Jokes aside, I also love that idea. Rebuild is just so much fun for me because we have new interpretations of each character, making it hard to predict their endgames.
Anyway regarding this scene, the fact that she looks like a younger Asuka and the shot looking greyer than the others give a flashback-y feeling.
While it never snows in Japan after the Second Impact, it should be noted that even after Near-Third Impact there's a part of the world that still snows (e.g. Wille's temporary base in the beginning of 3.0), wouldn't be impossible if this hypothetical flashback scene takes place in Europe, maybe somewhere in German or England. Maybe a scene with smol Asuka and Mari to flesh out these two's backstory'? They've been closely associated with each other in Rebuild and I think it's more than being fellow Eva pilots for the last fourteen years, their relationship is almost sister-like. We'll see.