Why is the albedo detail map multiplied by 2 in the Unity 5 Standard shader?

I’m playing around with the Unity 5 beta and its support for detail maps in the Standard shader for PBS lighting. I noticed (as the UI indicates) that the detail albedo is multiplied by 2. And that’s of course visible because of brighter textures as well.

36831-untitled.png

I’m sure there is a perfectly logical explanation for it. I just don’t see it. So my question is, why is it multiplied by 2? Why not use the detail map as is?

well im learning cg and i think that UV is a thing for the texture try putting UV2 into UV i dont know dont have unity 5 just guessing