Can someone explain mirror scene with Ariadne in Inception?

The scene is to demonstrate the limit of her mind.

Earlier on, she was seen creating the folding road, something that her mind was able to rationalize based on the creativity that is allowed within her sub-conscious.

Within Inception, a lot of activity within dreams is based on seeing things. Notice the feel and weight of a totem actually tells someone whether they are dreaming on or not. It would seem that this (weight, touch) is not quantifiable when dreaming.

So to test the limit, of an infinite loop of reflections, seeing that light can only travel so far, what is actually going on beyond the mirror? Is it an actual reflection or are they looking at something parallel with the current projections within the dreams thereby recursing the hallways out of existing material (notice one end of the walkway ends before placing the mirror and now it follows with a new continuous bikepath and you cannot actually see the end of it)

So two ways it could be interpreted (in my opinion), either

• she broke the mirror herself to project the infinite walkway or
• the mirror broke due to the limit of the creativity of her conscious not knowing what exactly is behind the mirror (playing with the concept of a world behind a mirror)

The second seems less likely as it would end up in a discontinuity of the movie environment and Cobb's reaction. My bet is on the first way, she was trying to create an infinite hallway and the break symbolizes either her own actions to break it or the limit of her conscious to what exactly would be an infinite hallway.

Ariadne is in the process of changing the dream and Cobb’s subconscious senses the changes and begins to attack her. With the mirrors, Ariadne is discovering a way to create changes in the dream that Cobb’s mind can accept. In this instance, she creates an extended road that wasn’t there before. Cobb’s mind accepts the change in the dream because the two mirrors create the illusion of an extended road. All that is left for her to do is break the mirror and she successfully creates a road without bothering Cobb’s subconscious.

This explanation fits best with the context of the discussion between Cobb and Ariadne.

The scene takes place in Ariadne's second shared-dreaming experience with Cobb.

The purpose of this scene is for her to play around in the world, discovering that while she is in control, she can manipulate anything. This includes turning solid air into a mirror-door and also to show off some fancy visual effects in the movie (endless mirrors without showing a camera).

Other than that, there is no real cryptic explanation that I can find for this scene other than her playing around with the physics and her own creation skills within a dream. As well as enable the writer's to give some background to what shared dreaming actually is and the mechanics of it all (projections, extraction, etc)

As well as allowing a bit of eye-candy for the movie, I think it is used as a device by the writers to explain some of the background of the shared dreaming experience:

• The more you as an architect change the environment of the dream the more the projections are going to attack you. I guess this is done by the writers to place limits on what the architect can do in the dream. Stops the audience from saying 'why don't they just magic up a new route to the middle of the hospital'.

• That Mal is a projection that Cobb brings into the dream, and she is very antagonistic. We've already been introduced to Mal in the first dream in the movie, but this is the way that we are told she is Cobb's dead wife.

• That you should not make a dream space based on large areas of the real world - that you should only use detail and make a completely fake space so that you are always aware of when you are in a dream. This of course plays into the main theme of the movie in my opinion - is Cobb living in a dream?

EDIT: On balance I don't think I've answered the Mirror issue as well as phwd (+1), but I think these are important points that are brought into the scene with the mirror and the bridge.

I believe this scene has two meanings, one for Cobb and the other for Ariadne- one inside another.

I imagine that seeing the self in the infinite mirror and witnessing a breaking mirror could presents the conscious and subconscious to confront itself and change.

You will notice that they are completely alone in the scene between the mirrors and prior to the enclosure Cobb's subconscious was beginning to feel uneasy and threatened by the sudden changes to the dream world. Perhaps this paradox provided a solution. After the mirrors shattered the ease is restored and subconscious resumes it's existence. In a sense she forces his subconscious to change.

Also, it is clear that Ariadne posses a formative imagination and this is a display of that and her control. Mirrors in dreams are said to suggest a link or connection between the conscious and subconscious mind.