The potted blooming plant that Marian brings to the old age home is a central symbol in the story. It contributes to the cynical tone of the story in several ways.
One way of looking at the pot of flowers is that they are symbolic of the lives of the people trapped within the walls of the home. Like potted plants, they will not have the opportunity to outgrow their confinement. In this way, the potted flowers are a visual reminder of how the women at the home remain living only if they are cared for by others.
Aside from symbolizing confinement and a compromised existence, the potted flowers contribute to the story's cynical tone because Marian will receive extra points in the Campfire Girls if she brings them as a gift. In this way, they only function as currency; they buy a reward. They are not a thoughtfully-chosen gift to bring pleasure to an old woman. And because the woman puts them too high on top of a wardrobe to really be treasured or enjoyed, they don't seem to be especially appreciated. In fact, the woman asks Marian for money, which is clearly something she would rather have than a lovely pot of flowers. The gift is not thoughtful and it goes appreciated, making the giver and recipient uninvested in the contrived visit.