Eh, you should clarify that this is not an AOSP lockscreen. It looks like Huawei's EMUI, which is quite heavily modified and might simply be a translation error.

Meizu phone, Flyme UI. Equally as Chinese as the Huawei you mentioned, so your point stands. Whether or not a tranlation error though, the GP had never heard of anyone using 'password' in the context of a numeric pincode, but it does happen. Who knows, I could be biased through my repeated exposures to the Meizu lock-screen, but as a native English speaker I don't have a hard time imagining a numeric-only pin being referred to as a password.