How about both? You can produce images rendered by a game’s engine before a game is even playable. A developer can put every model in the map in the position he pleases, even the gunshots and bullets are positionable, control the lightening and put a camera in a corner and field of view that would be impossible or at least impractical from a gameplay point of view and take the shot. All this may be called fabrication but it can still be called ‘rendered by the game’s engine’ simply because it didn’t require any graphic editing by third party software.
And even without all the ‘staging’ people can be surprised how amazing screenshots can be made using simple pausing of the game and finding the right camera position and angle:
The original Halo game got allot of criticism for this. The first screenshots produced where made using the developer kit. Developer kits are just powerful beasts capable of rendering much better images then the console (the original xbox at the time) it develops for. All the screenshots were staged as well, giving much more interesting images then when you would take one from the boring first or third perspective.
From the Halo website:
How does Bungie make those cool screenshots, with no HUD, and no gun, and how are they so clear?
They start with a beta version of Halo and an Xbox dev kit (with extra hardware).
The photographer plays Halo normally, until he gets to a place where he wants to take a screenshot.
He then freezes the action.
At this point, he can step forward at frame-by frame speeds, if it’s not perfect yet. Once he’s happy with the location, he can ‘disconnect’ the camera from where it is and fly it to wherever he likes. It doesn’t even have to be a place that was visible from the original action.
Once he’s happy with the camera placement, he snaps the shot. He can define the SIZE of the snapped shot - it’s still in 640x480 increments, but he can define how many pieces to break it up into. A standard size seems to be 9 panes (3x3), resulting in a screenshot that’s 1920x1440 pixels. (Anti-Aliasing wouldn’t even be necessary - Tokamak)
These images are then transferred over to a pc, and resized for release on the web, in Photoshop.
THAT’S why they look so sharp, and THAT’S how they get such cool angles. 
I don’t think the ‘warning’ message was really fair. But still understandable, many people on different forums I showed this picture to called it a ‘bullshot’. But still it would be more fair to simply pick up that point (the perception many people get when they first see these screens) and explain why they look so great without ‘smearing’ (i know this wasn’t your intention) by saying it’s all a ‘photojob’. Just pointing out how such great effects can be achieved by using the game engine itself would be enough.
What’s more, it would even be a cool feature article for your magazine, exploring how professional screenshots are made. Maybe even add a quick tutorial how your readers can make their own ‘pro’ shots. Lots of games have a handful of commands that allows the player to pause the game, explore it freely and render high resolution shots.
