Please notice that you can independently assign the name of the folders in the Image gallery Folders configuration of the UI section.
For your customers it will be displayed this way:
For doing this please create it and provide the name of it for each language that you are going to support:
If you forget to apply the name for some language and initialize the Plugin for your customer with this language your customer will see the default names in this section (for example Folder1, Folder2, etc.)
Please let us know to email@example.com if it doesn't help you.