Hi caleb,
Wow, your post is very enlightening.
You see, as far as I can remember, I always have Dolphin configured to Show Previews as I prefer preview images of video files and if I recall correctly, the pdf and libreoffice icons always showed in their ‘original’ appearance.
Be that as it may, in the Preview tab in Dolphin I unchecked Office Documents and PostScript, PDF and DVI Files. This action ensures that the pdf and libreoffice icons show in their original appearance.
I suspect that previous distro upgrades changed the Dolphin preview configurations.
Thanks for pointing me in the right direction - I am going to check the Solution check-box.