Stills from the journal:
Mr. Robot is writing in Elliot's journal while he's asleep and teaching him how to draw cats
I wondered this before - but is Mr. Robot shooting him actually Elliot taking medication? Like they're trying to kill one persona, but they don't realise it's Elliot rather than Mr. Robot who is being 'erased'. In the scene when Gideon threatens him, the wound starts bleeding again (Elliot fading away?) and the Mr. Robot persona takes over, in his mind - walking up on Gideon and slitting his throat (the most extreme reaction possible/ a survival tactic).
He's been 'shot' once before - when they went to the shooting gallery on the way to Steel Mountain to help him shake withdrawal symptoms. He slammed the heroin and then he's shot before having the crazy vision.
He also makes reference to everyone at the game "being all happy and friendly" maybe they're medicated then too. That one game they showed was pretty bad tempered - what would make both teams suddenly change their demeanour?