The design, meaning and titles of the Harrow Deck seem to be designed to fit in with this campaign particularly, so no matter what the draw is, something will resonate with past, present and future happenings. Although I suggested a couple of additions to the reading, Ambrus had it pretty much nailed already.
For those who hadn't figured it out, there are six suits to the Harrow deck - Hammers, Keys, Shields, Books, Stars and Crowns, corresponding to the six ability scores Str, Con, Dex, Int, Wis and Cha. Each adventure in Crimson Throne is keyed around a different Harrow Suit for the Choosing (last one should have been Keys, but they don't tell you to only use that suit for the Choosing in Edge of Anarchy).
If you look at the placement of the suit symbol on each card, you'll see that it moves. Left to right is Lawful, Neutral, Chaotic. Top to bottom is Good, Neutral, Evil. So each suit has nine cards, one for each alignment.
It's a nifty little system to tie it all in with D&D attributes.
Oh, and those who were here at the start of the campaign, the first card that you got from Zellara wasn't a random choice. See if you can work out how it was made.