There is also an article in WW2-era Times magazine discussing similar stuff...
Yeah, and oddball called those times "the best".
More on topic:
It is heavily biased. Back in Australia, most of those white people liked to play with us about "guessing which Asian that guy/girl is." Most of them failed. Perhaps relying too much on misleading stereotypical guide like this.
Physical
The physical features are common stereotypes. It makes the Chinese looks better and Japs looks bad, it actually pretty hard to tell. It depends on which region they came from. Northern Chinese are pretty similar to the Japanese. Southern Chinese have more similar physical appearance to white people. Slanted eyes... there are a lot of Japanese with almond-shaped eyes as well. The only correct ones is the physical height, at that time most Japanese were shorter than average (nowadays it is irrelevant). Their nose peak can be a sign too, Japanese (and also Korean) tend to have high nose peak like white people do.
Pronunciation
Certainly this isn't mentioned, because the Chinese is the ally at that time. This is far easier to identify than forcing the suicidal Japanese captive to talk. Chinese (except foreign-born ones) have difficulties pronouncing "r" like the way latinos say "burrito". This is more apparent than the Japanese' difficulties in pronouncing "L" (which they instantly read with "r", like Ronald - Ronaru, Fly - Furai) or let alone long 's'.
Both read kanjis, and this is pretty funny.
你是谁？nee_EE SHER! SHAY
我要吃饭！waw_UH YAH!oo CHER FAHN with "FAHN" meaning rice, i hope WW2 GIs can suit themselves eating rice. And i notice that the word before '!' sign must be read with more emphasis.
Perhaps it is just like us couldn't differentiate Frankfurter accent from Berliner, Silesian, Bavarian, Westphalian, etc etc...
