There's a logistics leader! And with a couple teases on taxes, does that mean leaders are being reworked, and pops will have greater impacts on your empire? Could there also be supply lines? And/or dedicated patrol fleets/civilian ships?
And looking at it again, are they set up in a simplified chain of command (Minor leaders -> Governors -> Rulers)? Could there be leader loyalty to those governors, who in turn have a loyalty to the empire?
I know this specific picture is likely not for PC; but again, I can't see them adding these kinds of features to something that also isn't going to the PC version.
Also, different leaders have different clothes
EDIT: And the symbols at the bottom seem to be their traits.