You RFN, 2012

[Clodfobble]

I think maybe it depends on which direction the layers go.

If the outer hair is cut shorter than the inner hair, then it gives the visual impression of curving outward as well as makes the top layers less heavy, causing both visual and real lift.

If the inner hair has been cut shorter, it basically eliminates the underpinnings of the outer hair, causing it to be flatter than it would be with proper support.