There's no need to mount it first to burn it, even in the video you linked he doesn't do it(in fact, he actually unmounted it before showing how to burn it). The software only points to the iso/bin/whatever image file and that's enough.
I'm not familiar enough with playstation to know if they require a specific way to be burned to work(assuming you have a chip in your playstation of course), but it's something that's usually pretty straightforward. Should be easy to find out in a specialized forum.