When I look at this piece with a fresh mind, I first notice the painting and the profile of the model's face. The model, unlike others I've seen, actually looks focused on her work in front of her and has a nice focus about her. Her hair is pulled away from her face, realistically, and the brush in her hand seems used. It works well. The painting is decent enough, but has beautiful color choice. It draws the eye to the reflection point in the 'water' of the painting. From there, I want to look around at the table and paint supplies. Here is where I notice a few things wrong.
The cup of brushes is pulled too close to the models chest. It becomes an abnormal part of her form that is distracting and unnatural.
Next is her painting hand. It's pulled at an odd angle that appears to be resting on the painting, and I for one would not feel comfortable holding a brush that way, so it appears strange to me.
However, so far, everything is alright.
Then I notice the plain, navy backdrop and I'm finished. It clashes with the models dark brown hair, and the painting. In a small amount, the oranges and browns would work lovely with the navy blue, but there is just too much in the background that it appears heavy on the piece. Because of this visual weight, any nitpick I had before stands stronger to me, and yet there is more.
The painting is faced towards to viewer. The model is also faced angular towards the viewer. The feeling from this is unnatural. However, this is a glamor shot, so this is able to slide.
With that said, her off hand looks uncomfortable to me. I doubt this women could be bent over, with her hand in-between her legs on a stool, and with the painting hand in such a position, for very long. Even though this is a glamor shot, do not even find this pose appealing.

Technique wise, this is a very crisp shot. Very clear with no visible noise and nice lighting.

Overall, the backdrop choice really set me off on this one. Perhaps a few shades lighter, in a more mute color would be better.

And to add some personal taste to the piece.. perhaps add some mini shorts to the model. It would still add that spicy look I assume you were going for, and still keep the models form in tact. Personally, I don't find a unbuttoned shirt with a visible tank-top or bra underneath and no pants appealing; from a non-sexual standpoint. It would add some balance to the piece, and help with the rule of thirds.

[I don't usually write critiques. However, the two already submitted on this piece, I felt, were a little too generous. I feel the need to input my view on this work, seeing as it got a Daily Deviation and (of course) there is controversy over it.]

When I first saw this I said "Clothes would be a good idea about now" but as I looked at it I paid attention to the painting and her structure. I decided to not focuse on her lack of clothes but the art work itself. Her hair is perfect and her face is amazing. She looks serious about what she is doing and I see that. I like your idea very unique and un thought of by me. I just saw those paint brushes down there and thought Oh my, why is that there! But I thought it was diffrent. I hope you think about your technique. I don't love it but it is very unique its very diffrent. Good picture!