Michonne was mad when the Governor took her weapon. Now he stole her chains and she will be back... Again! He's really playing with the wrong person...

 

This. And the chain was a metaphor for showing the linking of the past to the present. When the Gov. was kneeling on the floor holding a collar in each hand, I thought it was clear that he was planning to chain Michonne between two walkers (presumably ones without their working bits removed).

Not sure if this is supposed to happen before or after the chair. *shudder*