Typically, extra labor -- that is rewarded -- for an art piece is going to be something that is pertinent for some common end.
Using Windows 95 to paint something doesn't add anything to the end of a piece.
Using marble and creating a structure that looks like a fluid river (or flowing something) adds value to the piece even though it was hard.
Using marble, period, adds value simply because the work is in marble (monetary value) and represents a skill that you can produce works of art in marble. Using Windows 95 means you can use dated technology to produce literally the same thing that Photoshop CS6 could product (most likely in less time): a JPG.
It literally is the same difference as painting a scene with your hands, and then doing it with your feet. Nothing was added and the work is no different, but you did it with your feet.
Again, how it's made forms the story around the piece. If you saw that painting in a jumble sale, with no story, it is irrelevant how it's made. But if you know it was painted with someone's feet, then that becomes part of your appreciation of it, and hence it can become more valuable to you.
I have a small framed bit of Chinese calligraphy ("Laugh") in my bedroom. It's nice in its own way, but nothing special. It was, however, given to me by my half-sister who I only got to know for a couple of years before she died from cancer. That bit of art has a particular story attached to it now, and that story makes it worth so much more to certain people (being 'me', basically) despite the art itself being mundane. The story associated with a piece has a value of its own, sometimes entirely orthogonal to the piece itself.
Using Windows 95 to paint something doesn't add anything to the end of a piece.
Using marble and creating a structure that looks like a fluid river (or flowing something) adds value to the piece even though it was hard.
Using marble, period, adds value simply because the work is in marble (monetary value) and represents a skill that you can produce works of art in marble. Using Windows 95 means you can use dated technology to produce literally the same thing that Photoshop CS6 could product (most likely in less time): a JPG.
It literally is the same difference as painting a scene with your hands, and then doing it with your feet. Nothing was added and the work is no different, but you did it with your feet.