Body Weight Standards In South Korea - pressure to be skinny

Hello! I’m white. Husband is Korean American. His mom is Korean, born and raised. All her friends in the USA are also Korean. My MIL best friend whole family is from Korea and she has a daughter who is maybe 35. My husband calls her noona. She’s nice, married with 1 kid. She is always posting pictures of the scale on Facebook any time she gains weight. She will go on crash diets and post pictures of the scale going down every day. But she’s skinny. I remember her posting about how terrible it was that she reached 116 pounds and had to diet then. Things that would clearly scream “eating disorder” to an American. Is this just generally accepted and done in Korean culture? I understand Asia uses different BMI than westerners because Asians generally have much smaller frames than us white people, but 116 pounds still seems SO thin in my opinion for a 35 year old woman. Not alarmingly thin, but definitely no reason to worry about dieting. I feel like I would be ripped a new one if I posted those kinds of things while already thin.