This great story concerns one man's struggle to accept the death of his wife as viewed by his daughter. You will want to consider how the father as a character is described and in particular how the narrator's reminiscences of him at the beginning of the story differ from her description of him at the end, and the impact this has on the mood.
When the story begins, the narrator remembers her father's hands and how they appeared to her:
My father's hands were huge. Slablike. When he was idle, they seemed to hang off the ends of his arms like two chunks of meat. He sat on his hands during the months he courted my mother.
Note how the size of his hands is emphasised. They are compared to slabs and "two chunks of meat," somehow indicating the strength of her father. However, note how at the end of the story, his hands are described very differently:
My father stood up and looked across the water to where I was crouched. Again I made the sound, again and again. He took three more small steps toward my side of the river and his hands fluttered like giant, tawny moths in the moonlight.
Remembrances of his wife show that his strength has been sapped or taken away. Grief has made his once-strong hands "flutter" as if they were moths. Descriptions such as this help create the sombre, sad mood that dominates this story about grief and loss.