I know some people who use g̶i̶t̶ ̶g̶a̶r̶d̶e̶n̶e̶r̶ gitfiti to draw on their commit history. Like NES and Atari sprites, like Pacman or Galaga. It's just meant to be a funny subversion of people who take GitHub graphs a little too seriously.
I've never had someone ask about my GitHub and it's on my resume. Probably because it's fairly inactive and I regularly take down projects I'm not proud of.
But man would it be hilarious to grill someone during an interview about this. "Oh wow! You're coding even on holidays! How about we do a quick look at your commits and you can tell us about your progress on some of these projects?"