Earlier quoted context omitted.
It's interesting (to me) in this specific example because it generates a favicon using SVG + emoji. I wasn't aware that could be done. Favicons can't be simple enoji/text, they have to be an image.
big thanks for the reply the grid is made up of fields, I thought you just could replace the sqiggly line (background) with an emoji/text using the right font etc instead of svg/emoji
No worries. And yes, but that's not what I'm taking about :) I was interested in the favicon, which is the icon shown in the (desktop) browser tab.