Contrasts

Reading Stephen King's IT (yes I've been reading four books at once, and yes, I've been reading IT since early 2006), I came across a scene in which young Beverly hears voices from the drain in her parents' apartment. We open the scene with Beverly, and then a quick paragraph on describing the bathroom:
The wallpaper in here was a hideous pattern of frogs on lily pads. It bulged and swayed over the lumpy plaster beneath. It was watermarked in some places, actually peeling away in others. The tub was rustmarked, the toilet seat cracked. On naked 40-watt bulb jutted from a porcelain socket over the basin. Beverly could remember - vaguely - that there had once been a light fixture, but it had broken some years ago and never replaced. The floor was covered with linoleum from which the pattern had faded except for a small patch under the sink.

Okay. Good description? Nice and succinct, giving us a feeling for the state of the dwelling, the age, how well off the people are... broken light fixture (link in with the abusive father? Maybe). We have our setting, perhaps grotty, perhaps we'd rather not be in there, but it's someone's bathroom and it's in its normal state.

THEN, over the next two pages the horror creeps back into the book, at first the voice of the lost child, and then the cackling, mewing, horror, and finally, the sink begins spurting blood, and calling out to Beverly that "We all float down here!" and then we get:

A gout of blood suddenly belched from the drain, splattering the sink and the mirror and the wallpaper with its frogs-and-lily-pads pattern. Beverly screamed, suddenly and piercingly. She backed away from the sink, struck the door, rebounded, clawed it open, and ran for the living room, where her father was just getting to his feet.

Aside from the fact that this, again, is a well-written, succinct paragraph that pushes the action immediately along (without any of my own personal style of pace-ruining), we get, in that first line, a return to the description of the bathroom, and the sudden contrast between what the bathroom was before, and what it is now. The normal world is still there, but it's laced with gore. And that contrast makes the image far more vivid in our minds.