Found this bug when playing with my friend. While he was inside the Mirror on the Lady Vengeance and I was out in the world I happened to use the teleport pyramid to get to where he was.
When I teleported, strange things happened for both me and my friend. On my friends screen, he saw my character appear next to his while on the respec/character creation screen inside the Mirror.
On my screen I appeared in some kind of void where probably all the assets for the mirrior scene is loaded.