Brint and Brienne have one for their respective magic sets, and Cait has one each for her Sun-Dancer and Witch sets. No-one else has a portrait for any alternate sets, but Azyrran does have an alternate bust for her bimbo set, likely because that bust was made for her other bimbo form. All of these, including Ryn, have alternate combat headshots for those sets.
The idea is that EVENTUALLY every set will at least have its own combat headshot.... Assuming it changes anything above the shoulders. Like I'm pretty sure Kiyo's sets are just her switching spellbooks.
Moira's also drawn a rough draft of Hexblade!Cait so that's probably going to get into the game at some point, along with a completed piece for a currently unimplemented set for Ryn that's waiting on whatever content the set itself is gated behind.