I have been receiving conflicting information, both from forum posts and from AppleCare. Apple reps have told me that there a...
That's the SIM card receptacle.
I know this comment is a little late, but you said that this was a German iPhone 4S, right? Have you done a tear down an either an AT&T version of the retail unlocked version of the 4S?
Perfect! I didn't disconnect it and the cable had plenty of slack! Great job!