Don’t believe the claim that I, Elizabeth makes to “reveal the woman behind the queen”. The play is far more complex and ambitious than that. When Elizabeth observes that “princes are set on stages”, this is not an empty reference to an Elizabethan trope, nor merely being self-referential.
The pressure of the public spotlight threatens to destroy Elizabeth's carefully cultivated appearance. As the lights flicker and threaten to go out, her cries of “Oh, God!” become less an of exclamation of grief than a direct address to the deity whom she believes has singled her out. In her words, “It is so difficult to know the difference between seeming and being”.