I think this would make a kinda fun flashcard game. How many can you recognize without the hair/hat?
Kaguya because the symmetry. Remilia (EoSD) and Satori are also impossible to miss thanks to how different from the usual ZUN-style they look. Parsee because her ears are showing. Kogasa because duh.
I tried to see if I can recognize every character here from just their face without scrolling over the notes or looking at pictures of their portraits:
Also I didnt go back and look for the ones I couldnt recognize.
Edit: After comparing my list with the picture I... got everything I could recognize (all but 3 which to be fair are playables who have a lot of portraits) right. I think I have a problem...