What was the significance of the older dark haired lady on the subway at the beginning of the film?

The lady who just blankly stares at Jake after he asks her if the train passed his stop yet - was she a character of significance to the plot/development of the story? Aside from her giving Jake a wide eyed stare as she did not verbally acknowledge him, she did not seem to be as bizarre as other entities that Jake encounters as the film progresses. Was her presence supposed to have symbolic meaning or was she just put in the film to set the tone of bizarreness?