What counts as artificial illumination?

[Ringtail]

Question is as the title.

I was reading the Shadow Demon's statistic block in the PRD and noticed that its Shadow Blend ability is not negated by artifical illumination. Looking over the Vision and Light section of the CRB, I must be missing where artificial illumination is defined.

Light spells must not be (since Shadow Blend states that it is not negated by articial illumination or light spells, implying that they are seperate), so that leaves alchemical items (sunrods), creature/terrain abilities (phosphorescent fungus), and mundane fire (candles, torches, and so on). The term artificial illumination is throwing me off, because I can't find it defined anywhere and fires provide very real light.

Hmm...if you made a silent image of light in a pitch black area, would only creatures with darkvision be able to see it since figments can't create real effects (like light)?

[LastNameOnEarth]

I would guess that anything that is not sunlight, or does not create true daylight is artificial illumination.

[LazarX]

Any light that doesn't come from the sky. Certain natural light sources will act like artificial ones, and are treated as such.

[Lincoln Hills]

One does wonder why they didn't just go with the usual "bright light negates this effect." At least then they'd be using a consistent term... albeit one differently defined than "natural light".