“蓝瘦香菇” "blue skinny mushroom" became an internet phenomenon in China almost overnight. It is however not about mushroom. The “蓝瘦香菇" (meaning blue skinny mushroom) is pronounced very similar to "feel bad, want to cry" 难受，想哭 in a local dialect from Nanning, a city in southern China.
But to the opposite, you just can't stop laughing after watching it because it does sound like he's kept saying "blue skinny mushroom".
Further more, the young man from the original video opened his official weibo account with Sina Weibo microblog site after his upset face was widely spreaded on internet. He looks quite happy now with over 280K followers and had started his own first livestream yesterday.