This short format workshop is useful when a team has a narrowly scoped challenge but a number of stakeholders with different ideas on how to solve it. By bringing together a cross-functional (UX, ENG, Product) group the team can align more quickly on the best solutions to pursue and quickly expand the potential solutions available for testing.

If you have a team that has been working together for awhile and has alot of shared knowledge you can keep the lightning talks short to just restating the important data to help inform the challenge.

I always save a little extra time at the end to document everything thoroughly for future prototyping.