This strip is entirely referencing previous instances in Zombie Roomie that deal with the circumstances at hand.
First, George sold his soul to remove the zombie virus from Zoey
And second, Zoey assumed George was too far gone when he was rezombified and went to blow his brains out
... only to have him snap out of it at the last second and she killed the television instead
The continuity of how whether zombies are more like in the movies or more like George was something that I thought needed to be addressed again for this section of this arc. So that's where this particular strip came from.