Not just a narrative of what happened in what order.
Why did your team do things in the way they did them?
Reasons can be rational (we worked out this was the best way of doing it) or related to culture (it was what we felt comfortable doing).
What did you think and feel about the outcomes?
(Yes, you can discuss feelings in a reflective essay)
What kind of assumptions were you making?
And how justified did they turn out to be?
Above all …… what would you do differently in future?