Responses

Personally, I think BOTH Nephthys #1 and Nephthys #2 are real, she was just split in two. It's just that the one outside is her unconsciousm, the unrestrained side that always acts out on her emotions (which is why she's so darn irrational) and the one inside the mirror is her "perfect god" side: Normally, the unconscious would be the one locked up, and her "rational god" side would be the one out, but someone switched them over.
Everytime i see nephthys i always start to wonder what happened to the real one trapped in the mirror and why she hasnt been mentioned yet ┗( T﹏T )┛