Since Store Commander is a 100% web application, your images needs to be stored on a server (FTP).
In your CSV file, the column dedicated to images will indicate the location of the image files (for SC to fetch during the import process).
2 options are available to you:
Store your image files on your server, for example in https://www.yourstore.com/files/images/TE-01.jpg
> in this instance, this full URL will be used in the CSV file
Store your image files on your FTP in /modules/storecommander/import/images/TE-03.jpg
> in this case, your CSV file will only need to include the filename TE-03.jpg
Note that you can create sub-folders in /modules/storecommander/import/images, such as /modules/storecommander/import/images/cushions.
In this case, your CSV file will need to include /cushions/image01.jpg.