I think he means that good design aligns with the materials used and is straightforward about it’s purpose. A coffee pot isn’t made of wax paper, it’s made of materials that support the heat and liquids that you put through it. And a good coffee maker isn’t trying to do anything more than it’s intended purpose: make good coffee. It’s where you start defining what “good” coffee is that you get into those interesting variations on a theme…
In user experience design, I have often said a variation of this (and I plan on writing an article on this, someday): design what is true. Make the design be useful and straightforward and simple – don’t confuse users by trying to provide an abstraction instead of a solution. Good design doesn’t mislead or fight with the user – it’s honest and, well, true.