The story
From China + -ese under influence of Portuguese chinês, replacing older Chinish. Doublet of chinois. In its orientalist sense of "generically exotic, backwards, or poorly organized", sometimes a deliberate marketing strategy to increase sales, as with the German Chinese checkers. In its sense related to the orientation of stage lighting's barn doors, a reference to a supposed resemblance to East Asian eyes.
Etymology from Wiktionary, CC BY-SA 4.0.