The method used is tilt shift, using a special tilt shift camera more widely used in architectural photography. There's 2 panes of glass inside it which make some parts of the image blurred and some parts sharp, and it's this, plus saturation and contrast to an extent, that makes it look miniature. See also Barbieri's film Site Specific_Roma and most of his photography work. I am fascinated by Barbieri's work, I love the manner in which it makes us re-evaluate images we thought we knew well, by presenting them in an unusual manner. When I first saw Site Specific_Roma at a gallery I spent a long time trying to figure out whether it was or wasn't a film of miniatures- his work looks even better on a big screen or projector.