So I am wondering about ... ethics isn't quite the right word... maybe I'll settle for how much you can get away with.
If someone sees an awesome, amazing photo that was very original and quite unique, and then executed that very same photo and managed to get something that was also a very wonderful image, is it okay to post it on a largely anonymous internet forum? What about publish it in a book?
Even though it was pretty much identical?
As an example, a reasonably popular deviantart pic called "Bear in a Cat" of a white cat's paw... If I took it with my own white kitten and posted it, would that be okay? What if I changed it up by using my jet black kitten instead? The end result is an almost identical image...?
A second example, another deviantart pic call "f f" of a woman holding a couple of fish so that their eyes are in place of her eyes. It is a cool, surreal idea. If someone were to do the same thing, use that idea with a different model, perhaps even different fish, would that be okay to post as a cool idea on a forum? What about publishing in a book? Displaying in a gallery? The end result is different because the model (and maybe the fish) are different.
I hope you get the idea about what I am asking from this... Where do you draw the line and why? What is legal? How much plagiarising is ok?