How is Art (poetry,in particular) like the "belle dame" that the knight has been betrayed by in La Belle Dame Sans Merci?

In Keats's ballad "La Belle Dame Sans Merci," the knight, who is the speaker of the poem, tells of his misadventure with la belle dame, who steals his vitality and the vitality of other men who fall under the spell of her beauty and her song. Poetry, like other forms of art, can be understood as the belle dame if the reader of the poem considers the knight in the role of the poet writing the poetry.
Imagine a poet, like the knight in the ballad, happening upon something beautiful. This image, whether it be a vision or a sound or even a smell or taste, stays with the poet, who eventually obsesses over the beautiful image in his or her imagination, much like the knight obsesses over the lady in the meads.
While trying to translate the image into art, the poet struggles under the greatness and power of the beauty of the image, and eventually, the poet succumbs, weakened by the effort of trying to create something as beautiful as what inspired the art in the first place. This submission of the poet to poetry is like the submission of the knight, and the kings, princes and warriors before him, to the beauty of the belle dame sans merci. The creative impulse is as merciless as the belle dame in its power to overwhelm the artist poet and entrap him or her, leaving the artist feeling unfulfilled when creativity and art fail to materialize.