The span element's class is the only legend I could find.

  1) "liberal,young,poor,non-white"
  2) "liberal,old,non-white,woman"
  3) "conservative,poor,white,man" / "conservative,young,white,woman"
  4) "liberal,poor,woman"
  5) "liberal,young,rich,man"

The blocks aren’t strictly positional. Clicking them reveals a legend, but I thought they were clear enough: $ = rich, ¢ = not-rich, W = white, M = minority. So “D$W[male sign]” is “blue state, rich, white, male”. (Oddly, HN won’t let me insert the “male sign” character.)

Interesting. I could not get anything by clicking them in my browser.

This page explains the symbols: https://www.bloomberg.com/features/2016-america-divided/

(Ugly as sin though)

I must be the only person who adores Bloomberg's design/presentation. It's a very interesting intersection of flat-modern and brutalist, and completely unapologetic. So much of their content also features distinct art and layout in a way that conveys a special amount of care went into its publication, but always within a familiar design language.

I understand that it's not appealing to everyone, but I am always surprised at how much it gets ragged on.

You can click the symbols to see the category names

If you click and hold on the symbols, an overlay appears that decodes it.

I had to double-tap and hold... would never have got it without comments here - what a bizarre UI!

That's the ticket -- now I can see it.

Click it and you get a full page description.