Just them throwing insults.
Again, all China-reporting by the Western press follows a clear pattern: "China is incompetent and deceptively weak, but still you need to take care of them because they are bastards who can only win by backstabbing and using forbidden weapons."
To make China appear weak is not in their interest, since it will defeat their own fearmongering propaganda that serves to both keep their allies in line against the "common threat to freedom" that is China and to legitimate more defense spending, but on the other hand, a propaganda that makes China appear too strong would also defeat the purpose, since it would make their allies abandon their post in fear of Chinese strength and make them copy Duterte.
The best outcome of their propaganda is to make China appear like North Korea, a comically evil but incompetent country that should be feared for their unpredictable and backstabbing ways, but should not be feared for their non-existing strength.
It is just too bad that China seemingly plays along, since Chinese secrecy and ambiguity in military matters has the effect that it basically hands over the interpretive predominance to the Western propaganda organs.
So, as long as China does not show their strength, for example by openly stating what performance parameters the J-20 have or how many nukes China possesses, China cannot complain when the Western propaganda pushes through their claims that China is incompetent, weak and comically stupid-evil.
China should understand that world-opinion and deterrence doesnt work like a court-case, where the defendant can remain silent and let the lawyer speak for him. In the real world, remaining silent about oneselves means that you are what your enemies say about you. And if they say that you are weak and all people shouldnt respect your rights and interests because you are helpless in the face of violence, chances are that people will go and mug you. In that case, it doesnt matter whether you really arent helpless and weak - the fact that people already attempted to mug you and disrespect you is a big loss for you already.
China really should stop playing gentleman and start to reassert its interpretative authority - at least about oneself. You can see how well it works with Russia, who basically has nothing, but keeps talking about how strong they are... And it actually works, and noone dares to speak about blocking Russian access to Crimea, for example.
