I think they are trying another way to market slabs as the desirable way forward by 'assessing' beauty (which will always be in the eye of the beholder). Why else would a grading company which purports to assess the grade strictly on the degree of wear then give an aesthetic attribution - something they allegedly were trying to eliminate when getting the slab concept off the ground?
As far as a grading company is concerned, they should be consistently assessing the level of wear and the catalogued attribution. Everything else is irrelevant. Proof or not should be noted, but not prooflike. If cameo is used, then, Washer 01 should be an equally valid attributed grade, but I suppose they already have that with their M(ostly) S(mooth) designation.