What is the importance of The Black Box Theater in the novel, All’s Well?

Just before curtain time on opening night of All's Well, Miranda becomes enthralled by beautiful music that only she can hear, causing her to feel as if she were floating through the air to the source of the sound. The black box theater, a small alternative performance space without a proscenium stage, has mysteriously filled with an eager audience bearing strange tickets, and Miranda soon realizes that she is the star of the show that they have come to see. Awad does not give the reader any definitive evidence that what Miranda experiences in the black box happens in objective reality, is some psychotic episode or nervous breakdown, or is in fact magical forces working in her life, either through the brethren's handiwork or Ellie's spells and herbs. While under the lights in the black box, Miranda appears in what seem to be flashbacks to her earlier life with Paul, though with a baby named Ellie that Miranda does not remember having, suggesting an alternate reality.