Final answer:
The underlined stage direction creates a calm mood by reminding the reader of something soothing and relaxing.
Step-by-step explanation:
The underlined stage direction affects the mood of the scene by creating a calm mood as the reader is reminded of something that is typically used to pacify or soothe individuals. Rocking chairs are often associated with relaxation and comfort. This contrast of the calm image of a rocking chair with the tension and seriousness of the situation in the play creates an eerie and unsettling mood.
Learn more about The effect of stage directions on the mood of a scene