Previews in Info Panel of Office Documents Don't Work

Hello and thanks for your work on this flatpack. I notice that the Info Panel on the right does not show previews of Microsoft Word and Excel files -- it shows just a dummy image. Is there a way to get this feature functioning? - THANK YOU

Start by reproducing the issue in Dolphin's right-hand Info Panel with Microsoft Word and Excel files, confirming that a dummy image appears instead of a preview. Trace how the Flatpak handles these document previews and define done as working previews being shown for both file types.

Written by the indexing model from the issue text.