Here is an excellent, succinct set of slides which explain what the postmodern short story is and why it came about.
The postmodern short story came in the middle of the 20th century. Stories became anti-stories:
- plots lost cause and effect relationships
- “reality” appeared in quotation marks
- characters were flattened and artifice foregrounded
- symbols convoluted upon themselves.
— MARY ROHRBERGER