For more shots of how the NES scaling down works check out the
NES Resolution Explained page.

Adventure Island title	Darkwing Duck title	Bubble Bobble title
Adventures of Lolo title	Gunsmoke game	Micro Machines game
Super Mario Bros 2 game	Super Mario Bros 3 map	Super Mario Bros 3 game
Blaster Master title screen	Blaster Master intro	Blaster Master in-game
Lemmings title screen	Lemmings game screen	Kirby title screen

Comparisons
Between scaled (both background and sprites are scaled down), background scaled (only the background is scaled down) and unscaled mode (untouched original graphics).

Bubble Bobble scaled mode, you can see the entire screen	Bubble Bobble scaled background mode, the sprites look less squished	Bubble Bobble unscaled mode, a big chunk of the screen is cut off
Kirby in scaled mode	Kirby in scaled background mode, he's a bit rounder	Kirby in unscaled mode, the scoreboard can't be seen
Rainbow Islands in scaled mode, the rainbows looks a bit jagged	Rainbow Islands in scaled background mode, jaggies are even worse	Rainbow Islands in unscaled mode, the rainbows in their full size
Megaman in scaled mode, his face get a bit distorted	Megaman in scaled background mode, face looking better	Megaman in unscaled mode, looking perfect
Game selecting menu against a black backdrop	Game selecting menu against a white backdrop