The image above is the official Nokia service manual for the Lumia 920, detailing the product code parts and numbers, mostly for internal factory use and what not. However the folks at windowsmania.pl got their hands on a Lumia 920; and decided to pop it open and have a look for themselves.
First up we have the motherboard, which is attached to the internal framework of the device itself (yes that tiny thing).
Here we have what the phone looks like directly after popping off the back, note the charging plate on the back cover (beneath the camera) as well as the coil attaching the back cover to the battery.
This whole piece is the actual induction/charging coil (part of the back cover), the charging coil itself, along with the camera sensor and the curved glass itself are the main reasons behind the width and weight of the lumia 920 (the camera sensor alone is 7Mm).
Worth noting is that the 920 apparently has only one single speaker, I’m not one to judge before trying but that doesn’t sound to promising, especially since the speaker on the 900 is absolute garbage.