Translation:It is a city of fashion.
Can this mean "This is a fashionable city"?
I think that would translate as „To jest modne miasto.”
What the hell is a fashion city
Paris, Milan, etc. Those kind of cities that are important in the world of fashion.
Exactly, Milan is called "stolica mody" = "the capital of fashion".
Fasionable is more sensible
Well, maybe it is, but it's still an adjective - "modne miasto". As if all the citizens wore fashionable clothes.