I do not completely agree with the definition, but I do believe it is a start to the definition of art. Art doesn't just come from human expression though. Art is everywhere, in everything on the face of the planet and beyond the planet, it is created by every single being, organism, etc. You can literally see some form of art in everything you see, touch, taste, smell, hear, etc.
What I think is missing is the feeling, the heart, the soul, and so on that creates art. The meaning, the beauty, the feelings, the understanding, and everything that goes into creating art. Just need to take the time to actually see the art everywhere and appreciate the beauty and meaning behind who or what created the art.
My definition comes from both a subjective and objective perspective I believe. The reason being is that I would like people to really stop to look at their surroundings and take things in, art is not only a form of human expression, it is a form of expression for everything and is underappreciated.