What is CCP Decoder? What is its purpose? What need does it meet?

Right now, China’s internet -a world unto itself- and official media are praising an online post that seems, from beginning to end, to be an emoji nailing this bitterly angry moment for China.
This one post, endlessly reposted by People’s Daily and Xinhua news agency, is full of the coded keyword jargons in use in China, which so puzzle everyone else.