the idea is that instead of the skins being only client side, the client uploads his/her skins to the server, and everyone can see them.
now, before you say that people will just run skins that have no blocks, currently the server is able to check whether you have too many blocks in your player kv6 files, why not alter this so it also checks if you have too little blocks?
also, before you say the player will just make his skins one color, why not fix the skin check so that it also checks if the player is running too little of black color changing blocks in his KV6?
it would eliminate the ability to run revealing skins and give you an advantage.