It seems the arrest is more to do with the anti jingri laws than the cartoon specifically, and to be fair similar laws exist in Europe for holocaust deniers and Nazi glorification. There is a LONG history of hatred between the Japanese and the Chinese especially during the 20th century.
However though arresting a satirist is not on, nevertheless her activities seem not aimed at social change but at simple mockery and public outrage in which case she may have been better advised to have stayed in Japan.

Cool cartoon … Unfortunately the emperor, the great Xi DaDa, is not particularly impressed by humour, especially when it targets social injustices.

Wow

The article says the Chinese were arresting and punishing these sorts of social protest for years before they had passed a law against it. Funny ... the cartoon depicted what Chinese in the photo were doing.

It was the mahong games they had in the aisles, that people completely ignored the seatbelt sign and regularly had lifestock in the cabin with them! Dragonair was one of the scariest experiences of my life!