This reminds me of a book I read, and 2 women got caught in a world between 2 mirrors.

Each woman (separately) found themselves standing in a line of exact copies of themselves. Each was told "Which one is the real you? Find it, and you are free." One woman looked to her right and left, and began running down the line, examining each and every woman who had her eyes, her hair, her expression, determined to find the one that was really her.

The other woman simply patted her own body and said "This one."