Yes, the mural represents Queen Gunnhildr, but the clear implication is that if the idea of Gunnhildr were manifest as a Primal, it would take the form of Asura. If they didn't mean to imply this, they wouldn't have given her extra arms. These are things they do on purpose to hint toward what's coming, like when someone gave someone else a mirror with a moon design on the back, which was meant to foreshadow a certain primal.
