I found that a few of my newer `.docx` most `.pptx` actually contain a `docProps/thumbnail.jpeg` file we can extract. The samples I have are quite small, so please give it a try if you deal with those file types. Internet suggests it can also be `thumbnail.jpg` and `thmbnail.emf` (if Qt can even read that..) so the path isn't hardcoded for those.
The thumbnailer library name is kept to avoid changes when user updates and both do have "open" in the name :) I just dropped the Open Document Files suffix