Bjorn, since you haven't got a reply, I'll give you my opinion (caveat, I have NOT opened my set to verify).
I believe part of the "attachment method" for the front screen to the surrounding bezel is double sided tape. I'm sure there are other mechancial anchor points around the screen, also.
So what may have happened (due to transport or something) is that the screen popped back some and lost good adhesion on that side.
Unless it really is flapping around, I'm remiss in telling you to do something for fear you might further the damage (and perhaps void your warranty).
But if you want to pursue this is what I would do...
Use flashlight to get a good view on the edge of the screen while you push it back a little. Do you see sticky tape? is it pulling or completely lost connection to the bezel? Assuming so for some lengths, now try and figure how to apply pressure to get them back in contact. Perhaps just pushing on the bezel enough will compress them together. Perhaps you could access from the internal access ports on the side (but be aware you could really mess things up if you touch the "mirror" or drop something (tool, dust, dirt, arm hair!) down into the bottom where the lens assembly is). Perhaps you can find a suction cup to apply to the front of the screen that would allow you to pull the screen forward while pressing on the bezel. etc. etc.
But be careful.
