What is the significance of the Virginian roping the pony?

Wister uses the episode of the eponymous Virginian roping a recalcitrant pony as an opening illustration in his novel to show us the character of his protagonist and to underscore his skill as a horseman. The pony, Wister says, is one who "would not be caught, no matter who threw the rope." As such, the mysterious protagonist who can approach, and successfully rope, a pony who has neatly avoided capture by all others who have tried is set aside: through this episode, he is proven exceptional.
Wister describes the pony as akin to a "skilful boxer" and describes in detail how it outwits those who attempt to capture it, remaining "undistracted" throughout. At the side of the corral, the narrator observes "a man" who is also watchful and who approaches the pony with "the undulations of a tiger." Unlike the others, who have whirled their rope showily, the man watches quietly and approaches with no false showmanship but with an understanding of what the pony's attitude is and how it tends to move and react. Animal imagery is used again to describe the natural way in which the man approaches his task: like "a sudden snake," the rope ensnares the pony. The reaction of the passenger in the train epitomizes what Wister wants us to take from this story: "That man knows his business."