Jyoon and Shion usually have two different versions of their portraits, mostly because of the writing from the papers attached to Shion's dress. The writing isn't normally mirrored, so that's why there are two variants of the portraits.
However, in Gouyoku Ibun, their defeated portrait has only one variant, which is mirrored. The "opponent" variant is the original one in this case and the "player" one is the mirrored one.
To illustrate this better, I cropped the screenshots above to include only the Yorigami sisters and mirrored the ones where they were opponents. The results are as follows:
- when you mirror regular portraits, you can see that the writing from Shion's dress is different, meaning there are two variants of the portrait.
- when you mirror defeated portraits, you can see that the writing from Shion's dress is the same, meaning one portrait is the mirror of the other and there is only one variant for the defeated portrait.
Now, looking at the four cropped pictures from above, you can notice 3 of them have the same writing on the paper, while only one is different. We mirrored 2 pictures to match the perspective of the player, not the opponent, so this means the opponent portrait is the original one for the defeated expression.
Interestingly is that in the game files, there exist defeated portraits for both player and opponent (it's not just a mirroring created from code). The actual picture itself is mirrored from the very beginning.