Each participant tells a story about the last iteration that contains certain words Source: Philip Rogers
Provide everyone with something to write down their story. Then introduce the shaping words, which influence the story to be written:
If the last iteration could have been better: You set a couple of shaping words, e.g. such as 'mad, sad, glad' or 'keep, drop, add'. Additionally they have to write their story in first person. This avoids blaming others.
If the last iteration was successful: The team can either choose their own set of words or you can provide random words to unleash the team's creativity.
Now each participant writes a story of no more than 100 words about last iteration. They have to use each shaping word at least once. Timebox this to 5-10 minutes. When everyone's finished, they read out their stories. Afterwards lead a discussion about common themes of the stories.