In cosplay we have to make do with what we got. Most of us don't have an identical twin, unfortunately, making it hard to achieve perfect duplicates of ourselves. I suppose you could go the composite route but this photo was taken at a convention where both girls were hanging out and decided to do a fun picture idea together.
You're taking this too seriously, methinks.
Where did you get the chain from? looks so REAL! Oh, I know: You've stoled it from the game, right? You stoled it from Lara!
Here's a picture of it: [link]