The function of this cube is to look amazingly great and wow the customers. It achieves that. So the form definitely serves the function.
And if you think that two inch thick glass is a danger to anyone more than steel sheets or a brick wall of the same weight would be, you don't have the slightest clue.
I work in glass and if I had to guess, I would say that it's custom Laminated. Each panel is made of two or more sheets of toughened glass that are glued together with a PVB (think plastic) interlayer. Toughened glass is a lot stronger than plate glass, but when it breaks it shatters in to tiny pieces. In the case of custom laminated glass the bits are held in place by the PVB and don't rain down on the shoppers bellow.
I shot this 6.4 mm thick standard laminated glass with a potato cannon. Its still in one piece. You could shoot 51mm custom laminated with an artillary cannon.
New Glass OMG New Glass OMG. This is the most exciting news all day. I can't believe it! WAy to Go APPLe... You are so awesome and the bestest company Ever!!!