And lets me tell you my experience. I am an entrepreneur, (right now, I am in the process of my third business, my second business is paying my bills). I was a project in chief, i.e., who hired developers and it's tough to find a good developer. Right now, we are in the golden age of programmers, however, it doesn't mean that everybody is good but the opposite. Finding a good developer is tough. I even hired good-for-nothing people because I was short of alternative. So, if you want to be employed and you have a proper GitHub, then it will be straightforward to land a job.
People like me, hire developers, not because of the degree or years of work but:
b) price (sorry but it is part of the equation, cheaper + good = double as good)
c) Experience (technical experience).
And having a GitHub (a real GitHub, not only forks), it shows motivation.
About the image (the personal image), the last year, I participate in a Startup competition, I failed in the first round (they don't even call me back). I think that it was unfair because I am also profiting from my project, but I was wrong, startup competitions are not about money but image.
a) showing (at GitHub) who you are, helps a lot to be hired.
b) Creating a personal image is a must.