Thanks! :) And graphic design work would be greatly appreciated! I've done what I can, but I know it could be a lot better.
... I hope Google Groups will allow me some attached images. ...
I call the guys containing the call counts "pills":

Pills toggle between selected:

and deselected:

But they're tinted red if that function has ever thrown an exception. Selected:

and deselected:

When a pill is selected, it gets assigned a glyph. In that first example the glyph was a red square, and in the exception example the glyph was a green circle. The glyph serves as an identifier for the function that carries over into the log:
Items in the log from Node.js get a green background. Items from Chrome get a yellow background.
I've found that the circles and squares look like they're supposed to indicate something rather than just serve as identifiers. When a function randomly gets assigned a red circle, for example, people sometimes think it means something bad happened in the function. So Theseus should probably use another system.
I feel like that was comprehensive, but let me know if I didn't actually answer your question!