The camera of the Nokia Lumia 920 is the reason behind its "thickness"
"When comparing the upcoming Nokia Lumia 920 specs sheet with the other latest smartphone such as Samsung Galaxy S III or Apple iPhone 5, people criticized about the thickness of Lumia 920. Even though the numbers look big when comparing against its competitors, Lumia 920 is slimmer than Nokia Lumia 800 and Nokia Lumia 900. Its just 10.7 mm thick and the reason behind this thickness must be the camera sensor within it. As you can see in the image above, the camera sensor unit is almost 7mm thick.
This camera module packs Carl Zeiss optics, Optical Image Stabilization, 26mm Focal Length, F2.0 aperture, true 16:9 sensor, BIS and 8.7MP which allows us to take truly amazing photos and videos in any conditions. I think the thickness of the device was justified by Nokia by the features it embodies within it. Other than the camera, Lumia 920 has Wireless charging functionality, Pentaband LTE, NFC, 2000 mAh battery, PureMotion HD+ Display and the ever lasting Polycarbonate unibody design. What do you think?"
Seeing this sensor explains why the pictures of the Lumia 920 look so much better than every other phone out there. This helps me at least in accepting its thickness.