system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: The Chinese concept of Face

In particular, why does it cause loss of Face to point out that a person is behaving badly or inappropriately, but the person doesn't automatically lose Face simply by acting badly.
gpt
Face is just another word for ego. 

When you are able to pay the bill for the whole table after dinner, that's face.  If you are unable to pay for your meal (maybe you forgot your wallet) you lose face because it's almost as if you're trying to get out of paying because you are so poor. You're not, of course, you forgot your wallet but it FEELS that way because everyone will think you're poor, symbolically. 
Assuming again you are the one picking up the check-- it shows you have money and are able to pay for everyone else. It puts you in a position of power. Additionally, these people you paid for? They owe you an unspoken debt because you were nice to them. 
TLDR, face is like Chinese bling.