Harriet Monkhouse wrote about Blake's change in character:
At the start of the episode, Blake's face is smooth, bland and youthful.
He doesn't actually look like the Blake I know from the rest of the series until we see him in his cell, and then talking to Havant. How much of his memory has returned I don't know, but he's beginning to regain his dissident mindset. He looks older, stressed, but at the same time more vital.<
Having become used to the Blake of later episodes, it's fun to go back and watch him being such a model citizen.
Marian