I've always been fond of mirrors. They have powers: they can create a new world - reversing left and right - a new space, even a non-place where who's in front of the mirror is not at. Mirrors can show a place that seems real but actually isn't.
They can create a parallel reality, silent and suspended, where everyone can look at themselves, recognize or refuse to recognize themselves.
Gaia, looking at herself through a mirror, making friends with another herself.