Cosmetic enhancement mirror methods and related systems. For example, an improved biometric authentication system may also accept a user-inputted pass code derived from, and serving as a proxy for, the user’s biometric identifier. The present invention also relates to functional sweetener compositions and methods that can improve the tastes of non-caloric or low-caloric high-potency sweeteners by imparting a more sugar-like taste or characteristic. When an error is found, instead of stopping execution, the test operations to be performed are dynamically reconfigured. A receiving container receives the reflection plate, the light guiding plate and the light generating unit.