Hello! I don't know you, and you don't know me... But as I stumbled upon this deviation, I just had to give a critique!
Vision: Over all, I'll say that I can see the image clearly. However, the 'r' in the "Now I'll return the favour" is somewhat hard to see, but that doesn't really count now does it?
Originality: Okay... I see way too many of these split screen, split personality things. It's a common theme, but the expression and style is pretty unique.
Technique: I understand that you were playing around with effects. That's understandable, no worries~ The drawing itself looks flat, but the background adds depth to the drawing, which I like.
Impact: Over all it's a very nice piece. I love the expression and details. Everything is simply stunning~ Great job!
(I am horrid at giving critiques. orz)