The answer is: She sees the world through reflections in her mirror.
In the excerpt from "The Lady of Shalott," by Alfred Lord Tennyson, the weaver will be cursed to death if she looks down to Camelot, so she can only live if she sees the world through a mirror placed in front of her weaving machine. As a result, she becomes isolated and cannot see reality directly -she can only see shadows, the highway to Camelot and the knights.