This picture looks a lot like the SI pic in your link, bu then who cares.
Oh well, this one looks a lot more like it. The Doom2 demon you first presented was less of a lookalike, but this big fat (dude, I hated his damn missiles that could kill you in one shot) Demon is much more like the one on Halak's mask. The color is off tho. Might be a mix of the two.
I can't remember if that thread actually has his reasons for the design of his old mask so I'll mention what I've heard here in case it isn't covered. This is from memory so it might be a little off:
He had Roy lifting the Cup on there because he wanted something that relates to the Habs. I think he also said he was motivated to do the same thing when he got to the Habs. From what I remember, the bit on the top/front of his mask was something he thought looked cool. It might have a deeper significance (I can't remember if I heard that it did or if we just speculated about it a while back) but I think it is mainly for show. The bit on the other side, I have no idea about. The flag on the back is there for the obvious reason.
If anyone has more detailed or accurate info, please post it up.