They are all the real deal... Keep in mind that the first two shown on the site, man on couch and woman with trash can are sculptures with real props. So is the naked fat guy and the head on platform. As stated on the site, these are works by the amazing Ron Mueck. Check out the link if your a non believer. It will blow your gourd. Finally, the image listed first on this this thread of the girl's face is by Gottfried Helwein, an artist who has been working since the 80's. Keep in mind too that the painting of the girl measures nearly 6ft by 4ft, so it's no small work.
woooow... nice links... see this image, image like this is soooo difficult, check the details on each and every person in this painiting
The tegnique they use is called airbrush. My brother use that techniqeu when painting scal 1.16 tank models.