each character would be roughly 5 by 5 pixels.

then each 9 characters would be grouped into a 3 X 3 sub block like a face of a rubik's cube

and the larger code would be made up of these sub blocks

this would be analogous to paragraphs in written text

there is one billion websites. 1 billion is 30 bits.

let's say we go with 6 bits per character ( 64 distinct characters ) then we need just 5 characters to represent any website

a single 3 X 3 character sub block would be 9 characters where the first 5 or 6 are the information and the remaining ones are for error correction.

so just one sub-block would be enough to represent a link to any website. this could be easily drawn by hand.