Great question — answering as the UphillTech team:
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.
Full answer by sanpaco: https://movies.stackexchange.com/a/62465 (CC BY-SA 3.0).
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