game face

[KLPNO]

Hello everyone
I'd like to ask what 'game face' is:

Leaning forward in her chair, Penny said, louder: "Sit down and shut up."
Annabella, for the first time, seemed to notice that Penny wasn't in a mood to be trifled with. To be fair, Penny hadn't really put on her game face, as it were, until now. She had expected Annabella to react negatively, after all.

[riverkid]

Hello everyone
I'd like to ask what 'game face' is:

Leaning forward in her chair, Penny said, louder: "Sit down and shut up."
Annabella, for the first time, seemed to notice that Penny wasn't in a mood to be trifled with. To be fair, Penny hadn't really put on her game face, as it were, until now. She had expected Annabella to react negatively, after all.

Her serious face, the face someone would use before a big hockey/basketball/football game. One that let's the opposition know that they're serious.

[KLPNO]

Her serious face, the face someone would use before a big hockey/basketball/football game. One that let's the opposition know that they're serious.

Thank you very much, riverkid!