Or Best Buy... or Fries'... or your college Campus' coop store... or simply borrowing your friends' Mac.
You could have also said "and what about Steam ?".
Still, just saying, posting a screenshot of you using a Mac is not proof you own a Mac. It's only proof you posted to MacRumors using a Mac.
Post an image of you using your Mac. Please? I'm really interested if you look like I imagine.