@hwiii So this sentences its for answering someone in impolite way, am I right?

@kty40809 😳 Oh...thank you for your answer. I just saw it in a song that has this lyrics but don't know well what's the meaning of. Thank you for your help, 감사합니다^^

It just kind of ignored someone. Some time that word look like rude. A: why you are ugly? B: 응 니얼굴 Like that

it's nonformal..it means that you are ugly..