I doubt treatments or products for curly hair were popular in the nineties in Korea. that "magic straight perm" was actually popular back then, hence why everyone was getting it.
poster is not important, Idk why so many people complain about it so much...
because, when you're scrolling through this app to find new things to watch, one of the first things you'll notice is the poster. the poster is meant to catch your attention and make you click on the series/movie. it also gives you an idea about the actors playing in it, and what the series is about. that's why it's important for some people. I don't like the new poster cause you can barely tell who the 2 people in it are. so yeah, that's mainly it