A trash-can image in the mind map means the mind map is in the trash.
Deleting a local mind map moves it to the local trash folder. To remind you that you’ve deleted this mind map, the mind map displays a trash can image. To get rid of this, move the mind map to any other folder. The same applies to mind maps accidentally created in the trash folder.

Use “Empty Trash” to completely and irreversibly delete the mind maps in the trash folder.

trash-can image in mind map