How does the sewer scene from the Third Man use framing and composition techniques, mise en scene and cinematography to create meanings metaphors and effects?

Fig 1 

In figure 1, the composition of this huge arquitecture building in the image suggest to the

viewer that the character is caught in a really confusing maze  in which it's magnitude contrast dramatically with his size making him look reduced and small to the eye.

Each possible entrance is covered with darkness which make the viewer deduct that character will be lost, foreshadowing the tragic cirscuntances that can occur when he crosses one of them.It is also remarked by long shadows exceling from the deepness of the doors building the sense of tension and mystery.The parallels curved lines guide our eye in one direction focusing on a vanishing point in which is concentrated the light.

All theses factors cannotes the tension , a dramatic loneliness

Fig 2

German expressionism style is seen on the sharp line of the platform the men are on.The deep shadow and geometrical composition visually represent the moral and cultural anxiety that haunted Europe after WW2.

These connotations of anxiety and panic are heightened by the chiaroscuro lighting in which the deep key lighting constructs a big dark shadow reflected on the wall, right under the men, as making clear who is the villain in te film.The darkness of the shadow and it's dramatical size suggests moral ambiguity and crisis identity, linking it to The film l.a Noire where they also  used this techniques.

It can be detected that the men are looking for someone,the owner of the shadow, who is ridiculously closer to them than they thing.This situation plus the maze building reflect a metaphor of the hunt of the cat and the mouse.Unconsciously, the director foreshadowed to the viewer the end of the film creating this role-play and the hunting.

Fig13

In Figure 13 it's been iluminated  a specific spot in the scene making the image seem fragmented and therefore disorientated. This effect can also make the illuminated image seem enclosed and quite tight, bringing in also the claustrophobia effect.This makes the scene seem very claustrophobic as we can't see the whole surroundings, putting us out of our comfort zones. The aspect of the darkness makes our eyes strain, also putting us outside our comfort zone and therefore making us more disorientated.

Dark lighting surrounds all the way through the sequence, creating dark shadows in the tunnel from the characters. In relevance to the shadows of the characters, this creates moral ambiguity (As in fil Noir) within the scene as well as helping to disorientate us into who the character is.

 The deep lighting makes us disorientated as our eyes are not capable of adjusting fast in the dark, therefore  the usage of the dark lighting and dark shadows confuses our eyes as we try to adjust. 
A ray of light crosses the tunnel, defying the darkness that dwells there as a metaphor for hope.

The camera angle is high but aptly pointing inward the tunnel causing an effect of altitude and vertigo while the curved tunnel architecture reinforces this effect by adding a sense of continuity and claustrophobia.

Fig 6.

In Figure 6 it's been used conventions of film noir and aspects of media language:

Based on film Noir, the stair caise is a  visual metaphor for moral confusion , it's angular composition

within the sharp lineal shadows cannotes a sense of emprisionment as it seems cell bars; the shadow prison could explores issues of post-wars.

 The diagonals reflects how the director is using angular German Impressionism techniques as well to create visual manifestation of paranoia.

 Also the high angle of the shot  makes the image unbalanced and disturbed in perspective and helps to constucts a sense of disorientation.This enclosed up shot to the character's face emphaise a  massive claustrophobic feeling while the height of the shot creates feelings of vertigo

The up proceed light iluminates softly some places of the scene but still doesn't make disapear the eternal shadow covering the man's face, it represents moral crisis and connotations os anxiety and panic.

All these the compositions contructs a visual metaphor fot the character's situation.Harry Lime escaped into the sewers , being chased by the police. His eyes leads the viewer to a space we can  not see: the espape point

The camera angle, and the angular lighting creates a visual metaphor for moral distortion: The deep geometric composition visually represents the moral and cultural anxiety that haunted Europe after WW2, representing the sense of evil and fear thta seemed to lie within the grandeur.