MY THOUGHTS? As a guy looking at a half naked woman, my thoughts are not quite work safe, at all.
My thoughts on "why" this appeals to me seems to be that this crosses over in to the realm of fantasy. These "markings" make this person a little more alien, a little "less human" and I think part of us all desires to live in a reality where different types of humanoids existed. Its part of what makes the elven/dragon/etc high fantasy stuff appeal to us to begin with. We thrive on diversity, we WANT to be different, no one desires a nation of clones.
That said, god damn, that is such a fucking turn on. See my signature for details.