You may notice that library items file paths are not matching the associated paths in the workarea. For example, if in the workarea you have the folder path 'Departments Finance 03/2014', you may see library links which differ such as 'http://www.yourSite.com/departments/finance/march_2014/picture.png.'
This behaviour is usually expected. Library folder paths only match their associated links' paths when folders have not been renamed. If you rename a folder in the workarea the equivalent folder name in windows file explorer does not change. This is so that when a folder is renamed, existing links are not broken.
If you want to control how asset downloads are named, you're better off using DMS assets which can use the URL Aliasing feature of the product.