As is usually the case with fables, the focus here is on the illustration of an idea rather than on the exploration of character. The idea may have developed from Cortázar's perception of an inchoate longing to escape a crowded plane to the small island in the sea below; making the source of that desire an airline steward allows him to emphasize the need to escape repetitive activity and makes possible for him to underscore the increasing obsessiveness of the longing.
The central statement in the story that comes closest to expressing directly the idea that Cortázar wishes to explore here is: "None of it made any sense--flying three times a week at noon over Xiros was as unreal as dreaming three times a week that he was flying over Xiros." The story exploits the notion of the meaninglessness of repetitive reality and the increasing significance of desire. Whereas the protagonist cannot keep account of actuality, for everything is "blurred and easy and stupid," when he looks out the window at the island, it is sharply delineated, the nets clearly sketched on the sand.
As the story progresses, the fantasy out the window becomes more real than the reality inside the plane. However, as in Ambrose Bierce's "An Occurrence at Owl Creek Bridge," the transition from reality to fantasy is rendered ambiguous. It takes place when, "with his lips against the window, he smiled, thinking that he would climb to the green spot, that he would enter the sea of the northern coves naked, that he would fish for octopuses with the men, communicating through signs and laughter." Because his thoughts of actualizing his desires are rendered in such detail, the reader is lead to believe that he has physically gone to the island.
When Marini reaches the green spot in his imagination, he hears the hum of the engine of the plane. The question the reader may ask here is: where is Marini at this particular point--in the plane or at the green spot on the island? The final scene becomes even more ambiguous. On the one hand, the reader may assume that the real Marini falls to his death in the sea with the plane crash. However, since the only way the reader knows about the plane crash is by means of the fantasy that Marini is having while looking out the window, then the plane crash itself is not real, for Marini is imagining it also. The reader's ultimate realization may be that there is no reality in a story except the reality of fantasy.
Tomorrow: Donald Barthelme's "The Balloon"