Could've fooled me with that first chapter.

Though honestly, even I think she is unusually expressive here, even compared to the previous arc.
...
I've been thinking that for a while now, but maybe that's what the wall of 30 is about? The players growing too comfortable playing these games for their own good. They get emotionally used to it, losing the tension and fear, and with that, their edge. It starts to feel like routine to them, so they get clumsy and mess up. Maybe Yuki has become more expressive because she is letting down her guard.