Re: Mirror Scenes and Dialogue in TDK Trilogy
Are those Deus Ex Machina? Deus Ex Machina is when something conveniently saves the hero or the day at the last moment without being properly hinted at or set up before, to my estimation, removing the protagonist of the story from the conflict's solution. Throughout all those movies those various technologies are hinted at/established throughout the films, and in fact much of the plot revolves around them.
A better example of Deus Ex Machina would be Catwoman saving Batman out of the blue at the last moment right before he is killed by Bane (apparently with the Tumbler in stealth mode so nobody hears it driving through the door into the building...). It's not a total Deus Ex Machina since Batman is ultimately responsible for resolving the film's final conflict, but it acts like one in that it conveniently saves him from demise with no adequate set up.
I think you are more referring to the story trope of the MacGuffin, some artifact, machine or device which the plot revolves around or conveniently moves it forward. They can act LIKE a Deus Ex Machina (take the Ark in Raiders of the Lost Ark, it is the MacGuffin the film revolves around, and it is hinted at that opening it is a bad idea, but ultimately the literal "God from the Machine" saves the day at the end by killing all the Nazis--Indy is basically just a total bystander at that point) but are clearly established early in the film. They also act as somewhat weak Chekhov's Guns, though I think that more accurately describes things like Batman's flying gauntlet blades in The Dark Knight or the Bat's autopilot in The Dark Knight Returns (the flying gauntlet blades are the strongest Chekhov's Gun in the trilogy--they are only mentioned once, and never used until the climax of the film).
These are just my best guesses at definitions for the things, though...I might be all wet.