Does that really function? If I order socks audibly, I have no idea what I'm going to get. It's a lot more efficient to look through a page of images than to describe all the intricacies of my sock preferences via text to speech.
The idea is that the app would have some pre configured items that you've previously ordered - i.e. it already knows the brand, size, supplier, delivery method, etc. Its just providing a shortcut to place the order itself. I see this useful in regularly occuring basket items like food/groceries.