A comparison from the Flathub appdata quality guidelines, showing an "unacceptable" screenshot and an "acceptable" one. The unacceptable one is the GNOME contacts app, with no content. The acceptable one is from the same app, but with contacts of prominent communist figures, with the contact of Karl Marx currently selected.
https://ordinary.cafe/system/media_attachments/files/111/779/394/248/503/955/original/6ef20a2d2e7e2313.png