My guess is that under that platform is a jack set up. Seeing as how there is no lifting mechanism on the robot and a pneumatic set up is sitting off to the left. You can see an automotive jack here
http://en.wikipedia.org/wiki/Image:Nascarphx31.jpg
Or you can see one in motion if you watch this video
http://www.videojug.com/film/how-to-use-a-car-jack at around 4:00 minute mark.
Seems like a tried and true method of lifting heavy objects. Good luck guys, that looks pretty cool.