大洗女子vs大学選抜戦の助っ人に向かう直前にカチューシャ隊長が急に成長してしまい、萌え袖が見られなくなって悔しがるノンナさん。

It's Nonna-san who is feeling bitter that Commander Katyusha grew up right before the match of Ooarai Girls vs Selection University and she couldn't see the moe sleeves.

Refers to the fact that while wearing the Ooarai school uniform in the movie, the end of Katyusha's sleeves go well past the tips of her fingers.