What is the purpose of the Easterner's explanation about the Swede?

The Easterner’s analysis in paragraph 90 explains the
Swede’s uneasiness when he enters the hotel, but it does not explain his strange and
aggressive behavior. There is a conflict in the story between the conventional
expectations of violence on the frontier (which the Swede believes) and the beliefs of
the Romper natives, who assume that their town is civilized. The story is hence not
conventional; its realism brings out the individual causes of violence, even though this
violence stems out of codes that might fit frontier expectations. The characters are
individualized, then, but the results of the card game support the convention that the
American West at the end of the nineteenth century was characterized by much mayhem. The
irony of the story is that the Easterner is thus both right and wrong about the
dime-store novels. In effect the Swede becomes the victim of a self-fulfilling
prophecy.