I think it's the head/face, Kheto. Even by "heroic scale" standards, she's rather top-heavy. Not counting the impressive coiffure, she's only six heads tall (
in boots, no less!). Her facial features a bit oversized and stretched out, too.
Character sculpt aside, I absolutely love this piece. The painting is good, but grey-scale base/background are what really make the model, for me.
My only minor quibble is the scythe head - it looked great... once I found it.

I'm sure proper parallax vision makes it easier to pick up in person, but between the lack of color contrast and the mirrored curvature of the stonework behind it, the blade gets a bit lost. I'd have to think long and hard about going brighter with the metallics, though - it really does look great, on its own...