This is a powerful technique to analyze a current customer workflow. It does several things:
It makes the workflow visible in all its detailed glory
It clearly states the trigger and goals of the workflow (why is the user doing this? what are they trying to achieve?)
It captures pain points in the current workflow, designated by the color PINK. These pain points may come from various sources: common team knowledge, usability studies, customer complains, support cases, bug reports, etc.
It captures ideas for improving the workflow, designated by the color BLUE.
This is an artifact that a team can rally around and use to all get on the same page about what the workflow is, what the problems are, and how to improve it. It can be a living artifact that is updated as the workflow evolves and is improved.