On: What is with these candles next to Google results? Is this a seasonal artifact? (screenshot)

[terpua]

The images are coming from http://www.google.com/images/k3.gif

I thought it might be related to the keyword "solar" but looks like "solar module characterization" is the only thing that brings it out (I only tried 4 other combos with the word solar).

[pingswept → terpua]

I've been able to get it to happen more than once, but not every time. As far as I can tell, the candles only appear when there are ads on the right-hand side.