You can do all the postwork you want on an image...but as the OP points out..it's that certain something.....the artistic talent behind it that is what you are seeing and or feeling. Some artists postwork some do not. Some also do not use Poser as their actual render engine either. 

And while some of the artists mentioned may or may not trip my trigger, it doesn't take the "X" factor away from them.  It just means I'm not into their style.

But they are right, if you have the talent ....that innate something to be an artist, then it takes practicing of your craft to get the results you are seeing.  :)

Personally, I could care less if an image is postworked or not, I either like it or not...I certainly don't think that postwork is a dirty word :)