Someone on reddit suggested that what's causing this is skipping stages between/during level ups. Since I was hitting the space-bar quite often during that level up session last night, I just loaded up my save and went and re-spec-ed everyone with a glitched portrait without ever touching the space-bar.
And... it worked, everyone's back to their normal portrait shots... well.. if we can call Selunite SH sporting her DJ mugshot "normal" .. :P
Though this doesn't necessarily mean that skipping is what *truly* causes this. For starters: Last night when things glitched, I did a full party level up and this time I brought everyone over to Withers and then leveled them one at a time.
