I'm can't tell from the video if they used tape or glue. The stylist just said 'we have our adhesive in place.' A stock unit would be very close to the unit in density but without highlights (highlights are a custom order). Actually those are low lights. They used a color just a couple of shades lighter than the rest of the hair. It's adds a little 'depth' and realism to the piece. A highlight would be a high contrast color typically blonde. The unit in the video also appears to be wet or have product in it.