The first thing that comes to my mind is that this scanline thing would generate tall pixels.

This also fits with the way they're pixeled, because I've compared the sprites to their original sketches and they are always squashed vertically, as if they were making up for tall pixels.

Since we're considering pixels in such a close up level, I thought I might post (from wikipedia) an illustration of the two main methods of arraying pixels in CRT:
http://img.photobucket.com/albums/v165/talbot/ShadMaskVSAprGril.jpg-Shadow Mask (right): Which actually employs RGB triangles that flip vertically to make this pattern
B R G B R G B R G B R G
G B R G B R G B R G B R
B R G B R G B R G B R G
G B R G B R G B R G B R
B R G B R G B R G B R G
-Aperture grille (left): which arranges each channel (RGB) in neat little vertical lines, being closest to our square conception of pixels. Like so:
RGBRGBRGBRGB
RGBRGBRGBRGB
RGBRGBRGBRGB
RGBRGBRGBRGB
EDIT: wow! some aperture grilles actually dont line up vertically! they're more like
RGB RGB
RGB RGB
RGB RGB
RGB RGB
RGB RGB
RGB RGB
RGB RGB
RGB RGB That's nuts! I thought aperture grille was closest to square grids, but this actually means Shadow Mask is a little more reliable...c.c this makes pixeling quite different =O I mean just looking superficially we can see there a re 3 different ways in which pixelart can be displayed depending on Array method and manufacturer
http://en.wikipedia.org/wiki/Pixel_geometry Ok, I think this is the page we want to be looking at...this one actually focuses on the way in which subpixels are being distributed.
Apparently there's
Triangluar (delta)
Diagonal
Stripes

These show how there's no knowing which geometry they'll use...wether you're on LCD or CRT
did you notice how each displayed scanline in ptoing's pic also seems to alternate between bias for yellow and bias for red? These emergent color properties, and those random curves of color that seem to emerge are what interests me the most.
Ptoing, you think you can post the pixelart version of that C64 piece? maybe we can figure out what pixel array method it used....I'm betting on shadow mask

, 'cause of the yellow/red bias
I wonder if arcades have a standard of using only ApertureGrille or ShadowMask
