Thanks for the suggestions. I went there and moved the settings under "select GUI style" from GTK+ to Desktop settings, rebooted, no effect, then changed back, rebooted, still no effect.
1 - I installed PCMANFM and it is exhibiting the same behavior - no icons of any kind anywhere.
2 - I just noticed that in addition to Dolphin showing no icons, it isn't working to show even the names of the files in the file manager. PCMAN FM seems to be working and showing names, but no icons.
3 - I just noticed that Clementine is working fine, no issues, and I am able to select the MP3 directory I want using the file chooser just as normal, with icons, no issues.
Please let me know if you have other suggestions.