In a general I really like the brush strokes on the mask and the golden reflexes are spot on.
My only observation is how u rendered the ground. It's not really clear what kind of surface it is. If it's sand or fabric or mud, etc.
If u make the surface interact a bit more with the mask itself, the material of the ground can be more clear. For example, if it's sand, when u let a mask fall off the ground, it deepens a bit on the sand. And this kind of detail really can set better the mood and naturalitty of the scene.
And since the material of the mask seems metalic it should reflect a bit on the ground also (always depending on what kind of surface u determine it's going to be).

In an overall, thumbs up for the mask.

In my point of view, your image has a smooth yet sharp feeling to it. The brush strokes are just slightly blended in with each other, and I think that makes everything pull together and become one. Also, what looks like fabric is very well shaded, it gives it a nice 3-D feeling to it and it almost looks like velvet.
The lighting on the mask also looks very real. You have perfected the dark's, lights, and mid-tones not only on the main subject, but on the background and the entire image.

All together, you have done an amazing job. Keep up the good work!