When working in the Classic FotoWeb user interface, each thumbnail in your archive will have a "share" shortcut that lets you create an export for the picture (emphasized in red above).
Several exports can be created for each asset in your system, and a new, unique URL will be created every time you perform an export.
The CMS Export module has several settings that let you fine-tune the size and appearance of the exported picture.
These settings can be stored in presets to allow you to quickly pick a collection of settings the next time you do an export.