Use the mirrors as a metaphor, not a gimmick. Show a character stepping in and finding their own truth reflected back, then the world shifting as they go deeper. Keep the descriptions tight, let the illusion feel like a heartbeat that thumps the same rhythm in every paragraph. If you let the narrative slip into endless wonder without grounding it in what the character feels, readers will lose the illusion entirely. Remember, the real magic is what the mirrors do to the soul, not the shiny surfaces themselves.