I do not think art has to be representational or intentional. There are principles (i.e. line, form, color, light and shadow) that categorize art but cannot define if it is art or not. Unintentional art really moves me because it is more free and completely of a subconscious or by nature. I love the idea that cavemen painted their hallucinations.
My definition of "art" is anything and everything. Everything has an interesting line, everything is affected by light, everything is art.