There are a few reasons we do this

1. get stakeholders feedback on what has been done – How do you like it?
2. improve confidence in the product’s investment – What did you spend the money on?
3. maintain a rhythmic pattern of feedback –  Take small bites of work and feedback.
4. manage expectations – Help others see how this is evolving so they can position for optimal product success.
5. change direction as needed – Detect changes in direction early and often

If necessary, the Release Goals, Release Strategy, and Backlog are updated as part of the Review (or soon thereafter), taking into account the review and any “business reality” changes the Stakeholders may have . When teams are small we can rely on more intuitive reasoning to determine what the “right direction” is. As we scale we will see a need for more sophisticated techniques that use metrics to help us us answer what the “right direction” is.