The default language may not be English, but such is the nature of the Vakko site it overcomes any barriers thanks to its intuitive interface. The site is a great demonstration of how ecommerce should be done. It translates the shopping experience to the screen. You may not get the physical interaction of a shop assistant, but what you do get is choice with no high pressure sales pitch.
The site is very focused on its primary task and uses neat, and noticeably smooth and swift, animations to bring the focal point, the shirt into the action. Then it simply a matter of choosing from the vast array of options. These are much more than simple drop down lists or radio buttons, it a host of visual cues neatly order and broken down into palatable sections.
Start with the design and fit before moving on to the fabric, details, extras and measurements. Each time a new section is called into action the response is quick and sharp and again plenty of visual cues to head design the perfect custom shirt.
When all ecommerce sites get this good then we will be looking to do all our buying online.