A 52-year-old man from Delhi presents with a 3-week history of progressive weakness of the right side of his face. He reports difficulty closing his right eye, drooping of the right corner of his mouth, and loss of taste on the anterior two-thirds of the right tongue. On examination, the right side of the face is flaccid, and there is a firm, non-tender swelling over the right parotid region. CT imaging reveals a mass within the parotid gland compressing the facial nerve. Which anatomical relationship explains why a parotid gland pathology causes ipsilateral facial nerve palsy?