A timeless short story in the world of fiction usually has elements like cultural significance and the reflection of social issues. If it offers insights into different eras or sheds light on problems that are relevant across time, it becomes timeless. Additionally, a memorable style of writing can also contribute to its longevity.
The key lies in the depth of characters and the universality of themes. If the characters are relatable and the themes touch on common human experiences, the story can stand the test of time.
Often, it's the unique plot and the author's masterful storytelling. A plot that's full of surprises and twists, combined with vivid descriptions and engaging language, can make a short story timeless in the world of fiction. Also, the ability to evoke strong emotions in readers plays a significant role.