Why 33x48mm Is Different
Narrower and taller than the ICAO standard.
China's Exit-Entry Administration sets the passport photo at 33mm wide by 48mm tall. Nearly every other country in this part of the world uses 35x45mm, so the Chinese frame is 2mm narrower and 3mm taller — enough that a photo cut for one is visibly wrong for the other.
You cannot fix this by trimming a 35x45mm print. Trimming the width to 33mm does nothing about the missing 3mm of height, and stretching the image distorts the facial proportions the biometric check measures. Re-crop from the original instead.
