what expression? what pose?? we can only see 1/4 of her face
Looking at this bit of face from that angle remind me the plane expression of Kokoro. Of course we don't have enough element to judge, but the lack of element is actually a hint. We have a nose, an eyebrow, the high part of her maxilla and her little ear. You can tell if she's smiling, grinning, lifting her eyebrow and a lot's of thing, but here we don't see anything.
Most of the girls would be recognizable, even with such a close shot and the eyepatch, because of the expression they make (try looking at Ayane's grinning from that angle, you can't fail to recognize her in most of her victory poses).
Only two girls make really plane and empty expression which would give you a hard time to recognize from that angle : Momiji and Kokoro.
Both would be pretty plausible.
I revise my guess, I now think it's momiji.
(well I can also be totally wrong, I'm just trying hard to guess)