If you were coming in the fall
Housewife dismissing fly
Domestic simile for emotional control—she'd flick away three months like a minor annoyance. Notice 'half a smile and half a spurn,' the precise emotional ratio.
Months in balls
Yarn-winding image. Dickinson's turning time into a household task—organized, manageable, stored away until needed.
Van Diemen's land
Tasmania's colonial name—the furthest place from Massachusetts she could imagine. Her fingers would literally fall off from counting centuries before reaching that distance.
Life as rind
Orange peel logic: if reunion is certain in the afterlife, this life becomes disposable packaging. The casual violence of 'toss it yonder' is the point.
Goblin bee
Impossible creature—bees that threaten but never sting. Uncertainty is worse than any definite pain because you can't prepare for it.