New Character Concept Art, For you it's exciting, for Antiva, it's a Tuesday

To be honest, I always saw this as the woman posing for the picture rather than an indication of how she would actually fight. However, if she was standing more sideways on and pointing the sword forward instead of to the side, then it would be a decent enough fencing pose.

This is a case of the artist using style over realism. It was the same with the arcane archer, whose mask looked as though it would skewer their chest if they looked down.

The latest artwork solved this dilemma by showing that the mask is see through, so in fact rather similar to a fencing mask. However, people wear masks in fencing in order to avoid injury because you are essentially practicing for real combat. Also a fencing mask encloses the whole face and protects the neck as well. So even if she can see though it, the mask doesn't seem very practical and it is hard to fathom why she is using it other than for show. The standard, eye-slit Zorro type mask would be better if the intent is to conceal her identity.