The aunt is a kill-joy, a spoil-sport. We are not told this directly, but can infer it from her of habit of devising 'treats' for the children, for the sole purpose of excluding one or all of them as a punishment. She presumably does this in order better to assert her authority. From a child's point of view, she is an infuriating grown-up - she often doesn't listen when the children tell her things, and changes the subject when challenged.
We are told that she is a 'woman of few ideas, with immense powers of concentration' - a description which nails her as obsessive and small-minded. Nicholas is self-willed, stubborn and equally obsessive (about getting into the Lumber Room, and about thwarting the aunt) but he's a small boy. The aunt's obsession (with outwitting Nicholas) is revealed as actually very childish.
Nicholas is the 'hero' of this subtly subversive story. From the point of view of the narrative, she is the 'foil' against which Nicholas's character emerges - a boy of many ideas, imagination and quick wits. We applaud rather than condemn Nicholas's disobedience and his triumph in this war of wills, mostly because the aunt's behaviour is revealed as absurd, and she appears to deserve her 'punishment'.
Modeled after the two aunts who raised Saki, the aunt of "The Lumber Room" is autocratic, repressive, petty, and unimaginative. Nicholas's soi-aunt lacks the imagination to understand why Nicholas puts a frog in his bread-and-milk in order to expose her pettifogging nature. Instead, she falls for the boy's trick and demonstrates exactly what he knows about her; namely, her lack of appreciation of a child's creativity and her quibbling over trifles. Thus, she contributes to Saki's theme of the viciousness of mankind.
Putting a frog in his bowl is merely a boy's mischief, but Nicholas is punished by not being allowed to accompany his cousins and younger brother to Jagborough sands in the afternoon. The repressive aunt is always able "to improvise something of a festival nature from which the offender would be rigorously debarred."
However, Nicholas knows that the children will probably not have a good time. When his aunt forbids him to go into the gooseberry garden, Nicholas pretends that he really wants to enter this garden. So, the aunt busies herself with trivial activities outside the garden in order to keep watch over the two gates into this forbidden area. In the meantime, Nicholas sneaks into the lumber room, a secret room for which he has discovered the key.
This room, a "storehouse of unimagined pleasures," contains artistic articles that the aunt, who keeps the remainder of the house rather "bare and cheerless," feels should be locked away. In particular, Nicholas delights in a tapestry that depicts a hunter poised with his bow and arrow as two spotted dogs attentively wait for the release of the arrow before they join in the chase of this stag. In this woven moment of time, Nicholas wonders if the man and dogs have seen the four wolves racing in their direction, because he has only two arrows left in his quiver to defend himself against these predators.
Much like the wolves who come to wreak havoc on this scene, the aunt has spoiled Nicholas's creative exploit of the morning. After the aunt rushes into the gooseberry garden because she thinks she has seen Nicholas enter, she falls into a water tank. When she hears him nearby, she pleads with Nicholas to help her. With his arrow-like wit, Nicholas reminds her that he is not allowed in the garden; therefore, it must be the Devil who talks to him. Then, he leaves the aunt in her plight. She is not freed until hours later as a kitchen-maid, sent to pick some parsley, discovers her. Thus, both the aunt and Nicholas again contribute to the theme of the viciousness of mankind.
thank u so much ! :)