Final answer:
Aluminum dust powder is used on mirror-like surfaces to create a diffuse reflection by scattering light with its small, randomly oriented particles, which in turn diminishes shine for a matte effect.
Step-by-step explanation:
The type of powder in question is specifically designed for reducing the reflective qualities of mirror-like surfaces. When applied to such surfaces, the aluminum dust in the powder creates a diffuse reflection. This effect is due to the many small particles in the powder which possess randomly oriented surfaces, leading to a scattering of light in various directions, rather than a direct reflection back to the source. For instance, when powder takes the shine off of a person's nose, it utilizes the law of reflection, scattering light to create a matte effect, which is known as the diffuse reflection. The product mentioned, Undark, can be mixed with an adhesive to form a paste, then applied with a brush, adhering firmly to any surface to reduce shine for enhanced utility and appearance.