Here’s what I do to insert screenshot: make it, open it in editor, press Control+C, then go here, edit message and just press Control+V. And here you go.
What kind of icon is next to the album - a book or a tag? If tag, then this is not really an album, this is a tag. Tags are stored in image metadata, and if Tonfotos finds tags in your images, it automatically creates “tag-albums”. In current version they are not editable (to edit tags you actually need to edit source files). In future versions this functionality will be added.
If you have tags in your photos, that means those photos were already tagged by some other photo management application. You can open File Info panel and there is a chance there is a name of this application in file metadata.