Here we see the use of striking hexagonal imagery in the emblem of the Galactic Empire, proving that hexagons can be used for "evil" purposes by those who understand the subtle nuances of the Dark Side. Consider that the emblem of the Republic is a somewhat similar figure but with eight sides instead of six. It could very well be that this use of a weaker, less aesthetically pleasing symmetry is exactly what led to the latter's downfall in the first place. The Sith no doubt knew all along that a society based on octagonality would ultimately collapse before a more hexagonal alternative.
Consider as well that the Rebel Alliance never seemed to make use of the old octagonal symbolism. Since there was no way to improve on the Empire's hexagonal emblem, they went in a completely different direction with a sort of Zoroastrian-wing-type-thing.
This image is, I can only assume, the property of like Lucasfilm or something and its use here constitutes fair use under United States copyright law. Or so I claim, at any rate.