Both handsets are laid side-by-side in the picture, showing the difference between the 5.9-inch screen on Google's device and the 5.5-inch on Apple's.
The photo appears to back up several earlier rumours and mock-ups detailing the appearance of Google's latest which, this time around, is being manufactured by Motorola.
Independently of the above photo, US carrier AT&T seemingly confirmed the existence of the Nexus 6 by inadvertedly listing it for sale at $49.99 per month on contract.
Published on the carrier's online store, the link has since been changed to a redirect. Interestingly, the handset is the first in the Nexus line since 2010's Samsung-manufactured Nexus S to be available on AT&T.
The phone had originally been codenamed "Shamu" due to its 5.9-inch size and fittingly, Motorola has reportedly packed the stock Android device with flagship specs.
Behind the QHD display there's rumoured to be a 2.7GHz Snapdragon 805 CPU with Adreno 420 graphics, 3GB of RAM and a rear-facing 13MP camera capable of shooting in 4K.
Apart from the AT&T slip, we have no real idea about pricing although we've heard reports Google could announce the device later today.