These directories are maintained by X-Cart.
You should not upload images to the [images/(X)] folder directly.
These directories are used by X-Cart. For the import purpose you should upload the images e.g. to [var/tmp/(X)] folders.
Also, you should specify the "Directory where images are located" option on the import page.
X-Cart will copy them to the proper location automatically.
http://help.qtmsoft.com/index.php?title=X-Cart:Import-Export_Guide
http://help.qtmsoft.com/index.php?title=X-Cart:How_to_export_and_import_products_with_images