In the same way that water goes places where solids won't go, art goes places words won't go.
Language IS scrawny. By saying specific words, so much other "stuff" needs to be left out. What's more, many words do not necessarily retain the same meaning between the speaker and the listener.
At the same time, language tries to pin things down, rather than letting the listener decide upon meanings.
Many words have the same indisputable meaning between the speaker and the listener. For example, if I say, "Steve drove his new red car...", the meaning is unequivocal. There's not much wiggle room with the words "new" and "red" (the shade may be up for grabs).
But if I say, "Steve drove his beautiful new red car...", the word "beautiful" introduces more wiggle room. Our meanings for the word "new" and "red" are surely close to each other. However, my meaning for "beautiful" and your meaning for "beautiful" can vary greatly.
When art is used to communicate the idea of "Steve driving his new, red, car..." (like a picture or a painting), whatever makes the red car beautiful becomes better defined, and the details are stipulated (rather than being completely left up to the perceiver's imagination.) The art says more than a single word "beautiful" that could be open to many interpretations.
Beauty is ultimately in the eye of the beholder.