RLR2 represents the general sense of loss after someone died.
Mirror Mirror represents the pressure and lonliness of Weiss' life.
I Burn represents Yang's unkillable spirit.
From Shadows represents the story of a transitioning White Fang.
Gold represents Yang's committment to her sister's life, comforting her forever after her loss.
RLR1 is sort of up in the air, but I feel that it too represents a theme.
Just my opinions, what do you all think?