It looks like this is another sub-thread of the very popular Thong thread along with the Briefs thread and Panties thread.
I was one asking for larger avatar space nearly 10 years ago.
It's strange that Kakaotalk has well over 50 million users (about the same numbers and traffic as Line and Whatsapp, but far fewer than Weixin of Tencent), but no clear business model. It sells avatars and that's probably the biggest source of their negligible income. They all want to take share of the markets Facebook's best poised to dominate.
Kakaotalk does have some cool Kitty avatars.