From what I understand, the matte screen is a glossy screen before it's coated with an anti-reflective material. Supposedly, some consumers saw "unfinished" displays at a computer show and liked them, and manufacturers noticed that customers were more apt to purchase shiny laptops. Given the difference in reflectivity between such displays in different laptops, I deduce that glossy screens do have some anti-reflective coating, just not as much as matte.