You stick this thing over the lens, fire a test shot, the dome picks up the flash light and you use the resulting image as the custom white balance reference frame? Have a got that right?
If I'm understanding this correctly, it is a (rather unreliable) way of taking a custom white balance using flash. What is wrong with a piece of white or grey card, which you can actually position for consistently reliable results?
I don't like the marketing hyperbole either.