Huh? We've had commercial see-through displays for over a decade, of various qualities and features. Irrelevant here anyways since the schematic on the landing

Huh? We've had commercial see-through displays for over a decade, of various qualities and features. Irrelevant here anyways since the schematic on the landing page clearly shows that it's a small OLED in the top of the frame itself either angled directly at an eye or more likely using specially cut glass to make the image visible to you.