I am not an artist, though I appreciate art. I like some types, I don't like others, just like most humans. There's a great deal of art I don't understand, which itself is understandable: art is a way of expressing what is happening inside one's mind.
We all have different experiences, making a complete understanding of a piece of artwork impossible. But we have enough similar experiences that the work will translate-- it will just touch us all in a different way. It may even invoke a reaction totally unanticipated by the artist, but this is part and parcel of what makes art, well, art.
So when an artist says something like this, I have to react:
If I were [ET] trying to communicate with beings elsewhere in the universe...I'd try to express something about myself in the most universal language I could imagine: I'd send art.
My reaction? This guy is a goofball.
Art is the least universal communication method there is. It changes from person to person. Heck, it changes even in one person; I listen to Tchaikovsky as well as ABBA. It's difficult to understand art from another culture without first knowing something about that culture -- scholars still argue over the meaning of cave art from tens of thousands of years ago, and those guys were still human. This pretty much precludes understanding alien art, especially if it is sent via radio from another star without any sort of lesson in alien sociology. And even if it does invoke a reaction in us humans, it almost certainly won't be what the aliens had in mind.
Have no doubt, art is part of what it is to be human. That cave art I mentioned indicates that there was something different about the creatures who drew it over their ancient ancestors. Animals, it seems likely, don't grasp metaphors, and seeing the Universe metaphorically is what art is.
Metaphors depend on their context. I suspect that even if aliens had art, we wouldn't even recognize it as such.
The Universal language, if there is such a thing, is the language the Universe itself speaks: math. The symbols might change, but the relationships (like gravity dropping off with the square of the distance, and the peak wavelength emitted by a star depending linearly on temperature) are true everywhere.
I'm not trying to be a soulless scientist stereotype here; like I said, I have my own eye for art (I recently discovered Leonardo Nierman, and if anyone wants to buy me one of his paintings, there was a version of "Firebird" I saw in a gallery in New Orleans for only $15,000). Art is a way of expressing our desires, our fears, our human qualities... which is precisely what makes it such a terrible way to try to communicate with aliens.
There's a poetry in the idea of using art to communicate that appeals to our emotion, but poetry just won't work as a way to initiate contact. Binary streams of ones and zeros may seem cold and heartless... but aliens may in fact have lower body temperatures and no hearts.
Tip o' the paint-spattered beret to The Huge Entity.