Looking over some screencaps from this episode in a blog, this image caught my eye:
The way Mayuyu's hair is draped over Yukirin there is very d'aww-inspiring. So cute!
In regards to Nagisa's interruption, I have to agree with Kazu-kun. I also felt it was disrespectful to the person she was filling in for. Determination is all well and good, and making an announcement like that gains you respect in those quarters, I get that, but she could have showed her determination without interrupting the song, and she should have held her announcement until the break. Unfortunately, it seems she doesn't multitask well, so once she started thinking about how Yuuko and Chieri were leaving her behind, all other things she was supposed to be focusing on (like the performance she was in the middle of) flew out of her head.