I am a Japanese developer and am facing a huge trouble with iTunes Connect localization.
If your primary language on iTunes Connect is German, you need to enter the English description and screenshots for every localization (UK English, Italian, French, Japanese, ...). But what is problematic is the rest of the world which doesn't has particular localization settings (Australia, Canada, etc).
In these "rest of the world" countries, your primary language is used and we can't change it. In your case, the description and screenshots are displayed in German in these countries. In my case, it is in Japanese and this is a huge problem as Japanese is used ONLY in Japan! Actually, the sales figure of these countries are clearly low and in some countries, I received terrible comment and worst rate as my app is introduced in the language they are not familiar with.
I am asking Apple to solve this problem, but am not sure if they do something.