While viewing a page translation, the Edit tab is replaced by a a Translate tab.
However, when you click on the Translate tab, you are redirected to a fully different interface.
Tabs from previous page should be kept: you should be able to access easily to rendered page (Read), History and Discussion.
Current tabs (statistics and Export) should probably be moved on the left menu where we usually find that kind of tool.
Mainly, there is currently no link to translated page, whereas I (as a translator) need to view what I have done and to view messages in their context.
→ fixed by T270025