I think we can agree that making the dialogs and in particular the settings dialog more visually inviting is a good thing. However, two problems are priority and differing aesthetic opinions.  Some thoughts off the top of my head...

I consider revising tab contents a higher priority.  One thing is redoing the Highlights (Colors) and Keys pages using Mark's ideas from 5 years ago. At the time, Configdialog was a giant class with 70 methods and no tests.  3 years ago, Cheryl and I (with a bit of help from Louie Lu), split the class into a dialog class and classes for each tab, and added unit tests with, now, 94% coverage.

Also, the dialog is now too tall to fit in the space Apple allows to apps on my small Macbook Air notebook.  (See General comment below.)

As for the tabs themselves.  If left, 'Tabs' should be 'Indent', but the setting should be moved to General, which needs to be split into two pages (and classes) and tabs as there are other things to add.

I think 'Highlights' should be 'Colors', as 'syntax coloring' only loosely fits 'important parts' or 'lightened parts'.  Comments are colored separately so that they can be ignored.  Ditto, sometimes, for strings.

As for the icons, I don't think that the examples add much info.  Hence they seem like noise to me.  I think that the plug, possibly on an extension cord, fits best *because* it is so concordant with the text label.

If we do use images, I might consider emoji that get rendered on most systems.  Tk *will* display b/w astral emoji just fine in a read-only context.  Example: "\U0001f40d = 🐍"  This might be appropriate icon for one of the splits of General.  (Or we can create images that combine images and text.)

We could also consider creative typography.  'Fonts' in bold italic and varying size letters might better suggest 'font choice'.  Ditto for 'Colors' in multiple colors.  Boxing the 'K' of "Keys" in a key image or maybe even [K][E][Y]s might be interesting.

Now that we are using ttk widgets for dialogs, I have thought about somehow using Python yellow and blue in an IDLE dialog style.  But something else is always a higher priority.