Cobalt:  I was not referring to you, and I can see, sadly, in some instances it would be hard to express the meaning of the whole image, while cropping say, 90 percent of it out.  My comment was not intended to those instances.    No, it was towards the ones that either do not know, or "cant invest the time" to make a thumbnail at all, as their bases of argument.      However, even in instances where it could be hard to get the meaning across, I still have some slight contention with an image being 90 percent nudity........ I can't fathom say, a 600x800 image filled with only nude body parts. (though again I agree, something might get lost in translation of cropping).

The guidelines and TOS of the sight itself, sort of set the precidence for the content anyway.  Since no actual sex acts, manipulation or mastrubation is allowed in images....... one must assume, if it contains nudity (and by the genre of say, pin up, romance.... fantasy).  Again it could be a black square thumbnail, and the idea would be put across.

That being the case, and its again, only my opinion, if someone posted a nude under, for instance "Poser - Pinup", without even seeing the thumb I can make a good guess to what it contains.  Nude female, singular.  A thumb with a clip of the face and partial background can, indeed tell me the "Tone".  Also, even a close up of a minor detail can tell me the skill level, or "theme" of the "pin up".

Since I view nudes, and have no problem with them, the only invoncenience i see with the cropped or blank thumbnail, is occassionally i have no preview and go to the full size, and it does not "interest" me. (or worse lol).  However its a minor inconvenience, and IE graced me with a back arrow for just those occassions.  Slightly invonvenient, but hardly a hardship.

Again I still have the kevlar on, lol.  I certainly don't expect anyone to agree, its just my meager opinion.  The point, in closing, is that its worth it, by gum, to put a little thought / knowledge into a thumbnail to advertise an image that hopefully a lot of time was put into in the first place.