The Nexus is finally ready to reveal its secrets. Looks like that mystery connector belonged to the battery!

With cables decoupled, it's suddenly delightfully apparent why there were so many screws in the midframe. The Nexus 6 practically falls apart into two halves; the midframe/battery assembly, and the display/motherboard assembly.

Thanks to loads of screws, we don't have to deal with any adhesive, or even any tricky plastic clips.