“A Perfect Day for Bananafish” repeatedly uses situational irony, contrasting appearance and expectation with the underlying reality. Muriel, who is overly fixated on appearance, insists that this is a much-needed vacation and that Seymour is doing better. The atmosphere of the resort, the cheerful image of a child in a yellow swimsuit, the whimsy of the imagined bananafish, and the phrase "A Perfect Day" in the story's title all suggest warmth and happiness. But, beneath the surface, Seymour is in a state of turmoil and existential despair.
Readers glimpse his unhappiness in his inexplicable behavior, from his uncomfortable affection towards Sybil's feet to his snapping at the woman in the elevator. Still, these actions are so absurd and disconnected that they seem almost funny, despite the foreshadowing in the first scene that Seymour is dangerous. Seymour's suicide is abrupt and unexpected. After returning to his hotel room, he almost immediately shoots himself in the head. The direct, unceremonious death completely shatters the peace of the resort, the "perfect day," and the afterimage of the joyful, childish interaction Seymour has just had with Sybil. Seymour's circumstances, it's clear, are completely at odds with what's happening to him on an emotional level. Beneath the glittering surface that is Muriel's world of dresses and gossip, Seymour sees something hollow and terrifying.