If you put it on the same folder, FlickrUploader will not upload again.
For example: If you have a file in Family\myson.jpg , and you have another folder named MySister\Family\myson.jpg => When uploading, Flickr will create a new Album Family , and only 1 file myson.jpg will be uploaded.
Another case: If you have a file in Family\MySystem\myson.jpg , and you have another folder named MySister\Family\MyBorther\myson.jpg => When uploading, Flickr will create 2 albums (My Brother , My Sister), and 2 files myson.jpg will be uploaded (even if myson.jpg is the same).