The descriptions/synopses for iTunes Store movies are available in languages as supplied by the studios for your country or region (as set by your Apple ID billing address). The default would be to match the interface/device language, if available. Secondary would be the main language of the country or region, again if available. If neither are available, then the country of origin seems the most likely, or else the language of the local distributor studio representation.
If the distributor studio included neither English nor Norwegian descriptions for movies in the Norwegian iTunes Store, then they missed out on a very basic marketing tool, and thereby revenue.
You can give feedback to Apple (Feedback - Apple TV App - Apple), but change has to come from the supplying studios. Apple hasn’t made localized or English descriptions mandatory so far.
You can contact the responsible studio, see copyright line for that movie on its Details page. But there are much easier methods to accessing an English description, if you seek it.