poker face字面意思扑克脸，真实含义是毫无表情的脸；不动声色的脸。

【例句】
In business a poker face can be very useful.
生意场上，不动声色会非常有用。

I don't think I can pull the poker face to make it work!
我不认为我可以拉无表情，使其工作！