Under modernism, originality was very important as a break from old the classical aesthetics or the renaissance and ancient classical art, which seemed to just regurgitate endlessly. There was a big push in the late 1800s to try to get away from that, and originality was valued.
by the late-20th century, the American philosopher Richard Rorty responds to the postmodern movement and concludes that nothing is new, and that everything is essentially appropriated from something else, and furthermore our interpretations of that which we gain inspiration is determined by other experiences and "world views" which we hold.
Most postmodernists would throw up their hands and just say that "everything has been done and there is no sense in trying anything novel". But I think that this is a misunderstanding of postmodern appropriation. Rorty was known for kind of turning everything around to the point that his interpretations of Nietzsche, while logically sound based on what was written, do not take into account cultural or historical considerations, and that by "misreading" Nietzsche and appropriating his writings into our world view we do in fact create something novel.
Certainly when you look at art history there is a clear progression from, Jasper Johns or Pollock to Picasso and Braque to late Matisse and Derain to Monet. From there you can easily make connections to classical art. Each of these artists used what they knew about art to appropriate into their own experiences, creating something which transcends that which they appropriated.
So while originality was important to the modernists, postmodernists seem to embrace the fact that nothing is or can be completely original. After all, we don't live in a vacuum. However, the challenge arises when we seek to create something, rather than simply regurgitate it. With so many photographers being essentially modernist or new modernist (Adams, et al), I think we risk getting into that rut of emulation as we seek out aesthetic perfection.
That said, I wouldn't really classify levitation photography as "modern" due to it's "truthiness" (appearance of truth when in fact it is a lie), certainly Adams would not have been impressed.