There are plenty of examples of animals being taught to paint with interesting results. To answer what art is, I think it's important to eliminate the temptation to judge whether it's 'good' art or not. The impulse to create art might be specific to the process of communicating & translating abstract ideas beyond the borders of language, which I think is true for the earliest examples of human-made art. Contemporary artists are frequently the first to exploring latent ideas forming in the collective unconscious which is why they are associated with being trend-setters, and art historians can trace the origin of philosophic ideas alongside works of literature, music and visual arts.
'Good' art is recognized when the work expresses something profound, either through the intense discipline behind the craft or some transcendent truth it reveals. Masterful art can reveal the transcendent depth of human experience & potential, precocious art can connect adults to the world as represented by a child, etc. Like all forms of communication, it's a skill that can be mastered but that doesn't mean that naive art can't express some kind of significant aesthetic/symbolic truth.
It's difficult to narrow down because it's something deeply connected to the human experience. Art is likely a byproduct of our brains having evolved to design our own interpretations of reality & attribute meaning or purpose for everything we interact with.
There is a lot in this. What catches my eye is The impulse to create art might be specific to the process of communicating & translating abstract ideas beyond the borders of language
Not so much the translating of abstract ideas, but the "showing" of what these ideas are actually all about, nd in doing so reveal the material basis for a lot that is tossed about carelessly in "abstract" conversation. Art, in others words, underscores what is always already there in life and living. Dewey thought along these lines. Art is IN experience already in the crafts and the ideas that are what experience is made of. The making of something is inherently aesthetic.
But then, this does beg the question: what is experience? Art is an objective mirror, not of the world, but of our own interior, its "forms" and affectivity. One can say art IS the self objectified, revealing to the witnessing self a model of her own nature, and the importance of this lies in self revelation. I observe the world in the usual way, and thoughts of what I am become mixed with this world and its endless elaborations and arbitrary entanglements. Art takes me to something within that is lost. And this can be deeply profound.
One does have to be careful. The distance between art and insanity can be no more than a knife's edge. Think Virginia Woolf or Van Gogh.