|Greetings from the Critique Club!
Wow, your first challenge entry? Amazing capture! And great score too. Congratulations, and welcome to DPC!
I think the picture is great - creative, effective take on the challenge, extremely engaging portraiture, with some very interesting colours and patterns. I love the lady's steady gaze, and that slightly mysterious facial expression. And the interplay of light and shadow gives the picture a wonderful feeling of depth - the direction of the light works very well.
Not entirely sure about the composition. While I think it adds to the picture to have the folds of the scarf included as they are, that lovely engaging gaze seems rather awkwardly positioned at the top of the picture. I would've ideally maybe wanted to see it on one of the thirds lines, so it's possible that a tighter crop would work better? Not sure how well it would fit the challenge in that case though...
As has already been mentioned, the lighting is harsh. While I love the direction of the light you used, the harshness of it seems to result in some uncomfortable glare on the eyes, nose and chin, and also seems to make the model's every pore stand out. Maybe bouncing the light off a white piece of cardboard or a circular reflector could have accomplished a similar, but more gentle, flattering picture.
I think the focus works reasonably well. It might be nice if both the eyes were perfectly in focus, but I do think the picture works as it is. Advanced editing rules provide much more maneuvering space for post-processing modifications, which would've worked well for the image, but wouldn't have been allowed in this challenge, so I guess there's not much point in commenting on them... In terms of what you could've done in basic: I think the image would benefit from being a bit more contrasty, and maybe a warming filter to get rid of that bluish tint on her skin (if you were shooting in RAW, you could fix this by tweaking with the white balance).
Anyway, hope that helps. But well done, I think it's an excellent shot, and I look forward to seeing more entries from you in the future!
Any questions - just message me!