Rolad Dahl is a master of subtley. write down two details that a reader might miss on first time reading

There are two particular examples of Dahl's famed subtlety in "Lamb To The Slaughter" that I want to examine. I think they're important because they illustrate the wider theme of the story: the "worm that turned," or the moment where a poorly treated person strikes back.
Both examples take place after Mary has murdered her husband. In the first one, Mary talks to the grocer in an attempt to establish an alibi. On the face of it, their conversation appears straightforward. But if we look a little closer, we notice something significant. Mary mentions that she's going to prepare dinner for her husband when she gets home. But for the first time in the story she openly refers to her husband's name, Patrick. Now that he's safely dead he can be named. While alive, he was the embodiment of patriarchal power; but his death has deprived him of that power and he is now just a name.
A subtle manipulation of traditional gender relations is also evident in Mary's interactions with the police officers at her home. The policemen are very sympathetic to Mary's plight and are not in the least bit suspicious of her. They fetch her drinks, they provide emotional support, and, of course, they eat the evidence, the leg of lamb Mary used to murder Patrick.
For the whole of her married life, Mary adopted the traditional role of a meek, submissive wife. Now she has gained a sense of power and control which she exercises ever so subtly over the investigating officers. She has broken free of the gendered power relations that kept her in a state of submission. But the police officers are blissfully unaware of all this. They continue acting out their traditional roles by eating a meal prepared by a housewife and assuming that the killer they're looking for is a man.