This scene is so incredibly strong and meaningful
We’re in the middle of the fight between Eren and Annie, the two of them determined to win no matter the cost. We are used to this, we see it in all anime.
But here we see this colossal fight from another point of view, the one of a little girl, who sees her world crumble to pieces.
It’s even worse because, remember, we are in the richest part if the walls, here most of the people have never seen a Titan and live their lives in richness and peace. This little girl is clearly from a wealthy family herself, and surely she like all the rest of the population here were sure that nothing could happen to them: the threat of titans is a distant echo.
But now everything changed and each one of them is the same.
We could say that this, regardless the counter attack of humanity,
is a reference to the first episode: “that day humanity received a grim reminder…”