[jfrancis]

If you google the phrase 'Overpowering the sun' you'll see photographic examples of this effect. It's a popular look in fashion photography in which the model seems reasonably well lit from an artificial source while the sky takes on an eerie day-for-night quality.

http://www.youtube.com/watch?v=-hsm1MlDSWY

It's sort of a look at exposure and very mismatched lighting ratios.