I just find it questionable how people just love to point to plastic surgery right away when it comes to K-pop idols, but they won't do this when it comes to western celebrities. For western celebrities, they'll at least factor in makeup and weight loss or weight gain, but for K-pop idols, it's always speculation about plastic surgery.
And as someone who's gone through cycles of gaining and losing fat, the difference in my appearance (and the way I'm perceived) is night and day. People just don't like to talk about facial fat and how it affects attractiveness, but there's generally a subconscious preference for lower body fat percentage no matter how much people try to deny it.
Yeah. It really is questionable when you are comparing pre-teen pics/teen pics to adult pics. Puberty can do some wild things.
The appearance can differ depending on what kind of eyebrows you have. How far apart and the shape can drastically change the appearance.
Another example is Hanni having a round face, but her stylists covers the sides of her face with her hair to make her face look slimmer. Chaewon's nose in iz*one looked flat, yet the LSFRM nose looks sharper through makeup. If you see her side profile, its the same nose, but her look is completely different.
I think a nose job and double eye-lid surgeries are common, but aside from that, people don't go for the more extreme ones like jaw shaving, etc.