Problem: If you have a long backend page and you scroll down, the current locale scrolls out of view. If the working locale has scrolled out of view and something (e.g. a phone call) has made the editor loose his focus*, there is a risk that he will get back to work and overwrite content, e.g. insert English content in a Dutch translation or v.v. and only notice this after saving.

Does this look familiar?

So my suggestion is to discretely show the current locale in the viewport permanently, in a corner of the off-white area somewhere, not in the header since it is related to the content.

Alternatively, less subtle ways to do this would be to smack a position:sticky on the Current Locale- card, or attach a flag to the mouse/cursor.

*) https://www.youtube.com/watch?v=-kieJaT9EIA