What are the relationships between visible portions of the four images?

NOTE:
All these images are reduced. To see each one full size right use your browser
'show image' option on it (e.g. right click and 'show image' in firefox).
The top two images may be shown reduced if your browser is set to make images fit on
the screen. In firefox, if your cursor shows a "+" you can click to expand the image
to full size, and then use scroll-bars to look at different portions.

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                                                Figure A                                                                                        Figure B

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                                                Figure C                                                                                        Figure D

Questions:

1. What's the relationship between the scenes depicted in figure A and figure B?
2. What's the relationship between the scenes depicted in figure C and figure D?
3. What's the relationship between the scenes depicted in figure A and figure C?
4. What's the relationship between the scenes depicted in figure B and figure D?
5. Have important relationships been omitted from these questions?
6. What are the relationships between the relationships mentioned
   in the above questions?