In True Detective Season 1 Episode 6 Haunted Houses we see aged Maggie in the interrogation room with Papania and Gilbough. Her face is remarkably asymmetric: the left side is aged, wrinkled and gray while the right side is still young. Also, her hair on the left is dark and her hair on the right is light. What kind of symbolism is that?
I think you are reading into this too much. There is nothing symbolic here. The actress Michelle Monaghan simply has a naturally asymmetric face. I picked three images that I think show this fairly well.
I think that her natural characteristics along with a combination of lighting and makeup make this stand out in the scene you are referring to.