In a novel, this anecdote would be called an inset story — a complete and separate story set within the larger narrative. Black Elk repeats a story to entertain and emphasize the values of the group. The story shows the bravery and ingenuity of the courting Indian, for example, who risks death to try to take his lover. It depicts the traditional hostility between the Crow and the Sioux and turns the tables on the Crow, who had a reputation for horse thievery among the Sioux. The story emphasizes the importance of the horse and represents Indian courting and marriage practices. The Sioux did not have formal marriage ceremonies, but they valued fidelity and loyalty and observed clear moral standards in their sexual behavior. The tribe banished adulterers and promiscuous people, and sometimes the nose of the female culprit was cut off. Most Sioux were monogamous, although some men took multiple wives (Sitting Bull, for example, had two). The groom gave a dowry to the bride’s parents, indicating that something of value had exchanged hands. The girl in the story who is worth an entire herd of ponies is very valuable indeed, and High Horse’s act announces that publicly.
The story dramatizes a romantic love that most readers can empathize with. It also shows the importance of sharing stories as a friendly act and as a way to pass on the values of the tribe.