S3 partitioning strategy

fully aware of the documentations about how to name a S3 object within a bucket to optimize performance

can not understand the example in this article http://ift.tt/1MzEH0Z

2134857/gamedata/start.png
2134857/gamedata/resource.rsrc 
2134857/gamedata/results.txt
2134858/gamedata/start.png
2134858/gamedata/resource.rsrc
2134858/gamedata/results.txt
2134859/gamedata/start.png
2134859/gamedata/resource.rsrc
2134859/gamedata/results.txt

the article says "All these reads and writes will basically always go to the same partitio"

but we should have three partitions

2134857, 2134858, 2134859

, right ?

if we reverse the id

7584312/gamedata/start.png
7584312/gamedata/resource.rsrc
7584312/gamedata/results.txt
8584312/gamedata/start.png
8584312/gamedata/resource.rsrc
8584312/gamedata/results.txt
9584312/gamedata/start.png
9584312/gamedata/resource.rsrc
9584312/gamedata/results.txt

we have also three partitions 7584312, 8584312, 9584312

what is the difference.

What is the definition of a prefix and its relationship to partitioning strategy.