In "The Handsomest Drowned Man in the World" by Gabriel Garcia Marquez, a great change takes place in a remote village on a seaside cape after a beautiful drowned body washes to shore. How and why do the people in the village change after the appearance of this dead man?

The great size and beauty of the drowned stranger who washes up on their shores impresses and inspires the people of the village to become more than what they are or even imagined they could be before he arrived.
The dead man first appears covered in mud and scales. The women scrape him clean while the men go to the neighboring villages to find out if they are missing anyone. Even before he is scraped clean, however, the villagers are impressed with the drowned man's size and weight. When the women can actually see him, they are amazed with how handsome he is. They decide he is

the tallest, strongest, most virile, and best built man they had ever seen.

They call him Esteban. The name alludes to an Estevanico, a legendary man, considered by some to be the first African man to come to the American continent in the 1500s. Estevanico was understood to be a sort of superman who knew many languages, was a healer, and might even have been a god.
The women now want him to be buried properly, so they use wedding cloth and a large sail to make him clothes. When the tired men arrive back, however, they at first grumble at the women for their adoration of this man, but when one woman reveals his face by removing the handkerchief covering it, we learn that "the men were left breathless too." They also accept him as Esteban. We learn that even the least trusting men "shuddered in the marrow of their bones at Esteban's sincerity."
The villagers are changed for the better because of Esteban's magnificence. Their lives, formerly without flowers, now literally blossom as they festoon the corpse with blooms. As the story says, they

knew that everything would be different from then on, that their houses would have wider doors, higher ceilings, and stronger floors so that Esteban's memory could go everywhere.

They dream of planting flowers:

They were going to break their backs digging for springs among the stones and planting flowers on the cliffs so that in future years at dawn the passengers on great liners would awaken . . .

The flowers symbolize the villagers' transformation to new life. Esteban himself symbolizes how something new and different arriving in our everyday world can bring significant change. He becomes a role model for them and a blank slate onto which they can project their desires. Esteban therefore also symbolizes the power of the imagination. It is as if the villagers seize on this dead man and make him into their leader, kinsmen, and inspiration because they need such a figure to breathe new life into them. After all, we learn that the children had been "playing with him all afternoon, burying him in the sand and digging him up again." If they could bury and dig him up so easily, it is possible he was not as great as the adults make him out to be. This suggests that the adults want to exaggerate and idolize him. Esteban becomes the needed symbol of all their desires and their focal point for gaining the will to pursue their dreams.