Translators usually just get to see the string they are translatinbg, and if they're lucky a 1 sentence explanation written by a programmer.
With no context, a "Zip file" might indeed mean a "postcode file" - perhaps it is a file for storing all the zip codes, and now it will be used for storing all the postcodes?
It doesn't help that a lot of developers probably never translated an application; when I added translations the first thing I did was translate it myself, but that's not really feasible for larger systems and/or with people who don't speak a second language well enough to actually do translations.
https://media.discordapp.net/attachments/323831494718128130/...
This is French, English, German and JavaScript all in one sentence.
Two trillion dollar company.
So, you have to understand 2 languages to understand these listings.
I don't remember exact occurrences but I've noticed quite a few similar problems on macOS that are just the result of words being translated out of context.
On a popular forum software I used to do support for, "flag" (for moderation) was translated in French as "drapeau" for example. Which is technically correct I suppose, drapeau does mean flag, but the wavy kind of flag that countries like to use as symbols. Nothing else. And it's not a verb.
In this case, there is simply the string "zip" somewhere that is used both in some address forms and for the file type, and the translator just happened to translate the first occurrence probably without even knowing that is was also used in another context as well. Or without any means to ask the dev team to separate them into two terms. Which might not even be possible if they used too simplistic a translation system.