Hear a song that echoes cheerly (line 30)
On the face of it, this might not seem like it fits in the category of "art." Still, it's pretty clear that the Lady's song is something special. She isn't just humming here – when she sings, the people around her are enchanted. They stop and get quiet, as if she was casting a spell. It's the song that makes the reapers call her a "fairy" – one of a number of connections between art and magic. Plus it's her only way of communicating with the world, and that's a major function of art – it lets others know what's going on in your head.
There she weaves by night and day A magic web with colours gay. (lines 37-38)
This is the clearest example of art in the poem. The Lady is, more than anything else, a weaver. She sits and weaves around the clock. From what we can tell, her weaving is beautiful. A lot of women in the Middle Ages probably would have done some weaving, but the "gay colors" of this magic web let us know that she isn't weaving something like clothes. Her work is designed to be beautiful.
But in her web she still delights To weave the mirror's magic sights, (lines 64-65)
Another important side of the Lady's art is that it seems to make her happy. At least partly. It's a little bit of a contradiction. Here at least, she seems to really like weaving, turning what she sees in the mirror into something beautiful and permanent. Other lines, however, tell us that this isn't the whole story.