Allison's Discovery (Situational Irony)
Allison discovers computer programs that the silo uses to create false images of the outside world. This information compels Allison to commit the "great offense," as she believes the outside world is habitable and that the silo's leadership lies about it. However, the story's conclusion reveals that the computer programs were used not on the screens in the silo, but inside the cleaners' visors to make the outside world seem beautiful, which convinces the condemned to perform the cleaning. This reveal ironically subverts expectations, as up until the twist ending, it appears that Allison was correct in her conclusions.
The View (Situational Irony)
The massive screens in the underground silo project a single view of the surface world. Ironically, though the screen's image depicts a barren wasteland, the silo's citizens gather around it like it is a picturesque view. The silo sacrifices human lives to maintain this connection to the outside world, though the view is depressing and dismal.
Allison's Death (Dramatic Irony)
After establishing that Allison was sentenced to cleaning three years prior, the story cuts back to scenes from the end of Allison's life when she discovers the wiped records. Allison argues that she should release her files because "Knowing the truth is always good." This is an example of dramatic irony, as the reader understands that Allison "knowing the truth" resulted in her death sentence.
