-Reduce smoothness on the fill to 0 to see the effects
-Add bunch of fluff on one side
-Add a ColorMask to the fluff
-Have it be black to easier see the shine
-UV_offset the Color mask to fill the fluff more of the colour
-Mirror the fluff
You will see that the color mask adds a smoothness/Shine, not representing the smoothness it is on.
You will also see that the UV_Offset has not affected the mirroring counterpart.
I have recently discovered the use of colormasking the fluff for even more fluff usage, but it seems to produce some frustrations.