Flashing in roofing is a decorative process that is used to cover the metal flashing on a roof with asphalt shingles. Flashing protects the underlying membrane from water droplets and snow, which can cause leaks and damage.
The flashing is attached to the shingle using an adhesive, and then it's smoothed out using a hand leafblower or power sander. Finally, it's painted white so that it blends in with the roof color and prevents sunlight from reflecting off of it.