There are people out there who wish to be fairly restrictive about what is and isn't Art. Generally they want to include Rembrandt, Michelangelo, da Vinci, and so on, and exclude all that pesky modern crap, for some definition of modern.
In order to do so, they generally use the following approach:
- to INCLUDE things, they talk about what Art DOES. It enlarges us, it evokes an emotional reaction, etc.
- to EXCLUDE things, they talk about how Art is MADE. It's very difficult, takes years of practice, etc etc.
Indeed, by carefully, selectively, applying these two completely orthogonal definitions of what constitutes Art, you can make Art be anything particular list of specific objects or Artists you like.
If you're honest, however, you settle on one definition, and then you live with the consequences, which generally include a lot of things you wish were not Art, and exclude some things you wish were.
In modern times, we mainly use the first one. And then you do get oddities like a collection of snapshots, presented in such and such a way, is by golly Art. It's photography based, but it's really a conceptual piece, most likely. Whatever it is, people experience it as Art. They are enlarged, their minds are expanded, they react emotionally and learn something, probably something not describable in words. So what if it's snapshot? Or poop? Or a pickled cat? If it acts like Art, it's Art.
This is largely because if you go the other way and insist on defining Art by how it's Made, you wind up mostly with craft and artisanship, and a whole lot of beautiful well made objects that were very hard to create which are not Art by any meaningful standard. Really beautifully glazed pots and so on.
Poop or Pots? You gotta pick one.