Narrative Connection
How these two moments in the story relate
Why These Connect
The narrative assertion
"The Doctor's earlier demonstration of the Tardis's ability to change shape (via the scanner) sets up the thematic and functional context for his later attempt to 'measure' the police box, which is an attempt to recapture the Tardis's lost ability to blend in. This causal link underscores the Doctor's primary objective in the story: fixing the malfunctioning chameleon circuit."
About Causal Connections
A directly causes B. The first event sets forces in motion that produce the second. These are the load-bearing connections of plot--remove one and the story structure collapses.