According to an IMDb description of the 2015 project, Aniston stars as a "grieving mother suffering from chronic pain in the aftermath of a fatal car accident." That explains the scar -- and the dramatic makeunder, which finds the Friends actress with darker hair, very little makeup, and baggy clothes.
Aniston's new look was first revealed last week, when she was photographed in between scenes at a cemetery in L.A. on Thursday, April 3. She was dressed at the time in beige pants, a loose T-shirt, and an oversized gray cardigan.
Cake costars Anna Kendrick, The Mindy Project's Chris Messina, and Avatar's Sam Worthington, who plays the husband of a woman in a chronic pain support group. After the woman's suicide, Aniston's character develops a bond with Worthington's character, all while dealing with her own personal tragedy.