I think that Miller's play offers many of the previous themes that have been present in other works by the playwright. The fact that the setting is a mental institution helps to reflect one of the drama's fundamental ideas: that the social setting that many use to define "normality" or "acceptance" is severely flawed. Miller uses the opportunity of the two women befriending one another in the institution as a reflection of how he feels that there has to be a reexamination in what society values and how individuals are impacted by it. Miller points out that the women inside the institution are actually more emotionally close to one another and themselves than their husbands who visit them, revealing each couple to struggle to communicate with one another.
The play's critique of a social world in which money and success are accepted and one in which the lack of either by an external standard automatically determines failure is another salient point in how life inside the institution might make more sense than life outside of it. Miller uses the setting to help launch into a critique of the modern setting, having his characters reflect this reality in both characterizations and interactions with one another.