The Japanese word 顔芸 (kao-gei) is so descriptive. The kanji characters mean “face performance” and it refers to your ability to make facial expressions — to “bend” and distort your face in order to show expressions, reactions, and emotions. Think of Jim Carrey’s many faces as an example of extreme 顔芸.
Pixar characters are great at 顔芸 too:
I’m pretty good at 顔芸. Maybe it’s because of the culture I grew up in or the people I grew up with, but it’s also because of my job. Trying to get students to react is sometimes hard in this culture where 顔芸 is mostly relegated to comedians (to generalize). English class is a good chance to practice your ability to express yourself, both in words and in facial expressions. So give it a shot and try a happy face next time I ask, “How are you today?” Or show a confused face if you don’t understand. You don’t have to be Jim Carrey, but an unexpressive face makes you look like you don’t understand, aren’t paying attention, or are just bored. I know that’s not necessarily true in Japanese culture, but it is in the English speaking world (to generalize again). And we’re here to learn and practice not just the language but the culture, too.