What's all the bizarre, ually evocative imagery in Pokemon HeartGold SoulSilver during the Arceus event?

What's the deal with that? Pokemon isn't the kind of series to dispense heavy-handedness at players like this. They're more the type to patronize players by expecting all video gamers to be retarded ten-year-olds, because of the immature background from their own too-young society. So what's with all the photographic images and scary music when you fulfill the Arceus event to get yourself a Dialga/Palkia/Giratina?