Thru 'misused' of the plane of focus. In large format photography the plane of focus is often adjusted so that it is close to the plane of the ground, so that you have 'super deep DOF'. If instead, you tilt the plane of focus in the opposite direction, to 'super shallow DOF', you hit upon the 'miniature' look
But still.. why is it that the super shallow DOF tricks our eyes into thinking it's miniature? Take this photo for instance:
|IMAGE IS A REDIRECT OR MISSING!|
HTTP response: NOT FOUND | MIME changed to 'image/gif' | Redirected to error image by FLICKR
There's no frame of reference but it looks miniature.
Or this one..
IMAGE LINK: http://www.flickr.com …in/pool-tilt-shift-fakes/
My theory is that if that were really a model of Rome and our head was right in there above the town, we'd focus our eyes on one thing and the rest would be out of focus. If it were the real city and we were in a helicopter, basically everything would be in the same focus.. our eyes can't distinguish between 100 yards and 200 yards the same way they do between 1" and 2". Does that sound right?
*photos aren't mine, and both are faked tilt/shift. Click to get to their original flickr pages.