Discussed a decade or so ago, T: Illuminated is interesting as it has aspects of sensory magic and might be a useful addition to the special faerie duration: Fire. The idea is that the target may include anything which is illuminated by a light source. That light source may be mundane or magical, and can be anything from a candle, a roaring fire, or a magical beam of light.
Target: Illuminated (+2) The spell may affect any number of targets who are presently illuminated by a light source. The target is also expanded by an additional secondary light source per magnitude, where the secondary light source is within illumination range of the first. This allows a chain of illumination to be established. Illumination is also valid if spread or reflected by natural means (reflective water, mirrors, etc).
I think it is a clever extension to include non-magical reflection. If the illumination is spread in special natural ways by mirrors then the spell target is also manipulated. Likewise something which protects from illumination is also protected, so standing behind a barrier will allow somebody to avoid the spell; although the barrier itself would be valid.
A sample use could be:
Nonna’s Unbelievable Stories
Perdo Mentem 35, R: Voice, D: Fire, T: Illuminated
People illuminated by the targeted fire will believe almost any passable lie while the fire burns, even after they have left the light.
(Base 4, +2 Voice, +3 Fire, +2 Illuminated)