This is a very nice picture. The challenge states: Use a single, artificial light source to dramatically light the subject of your choice - the light source here isn't artificial, it's natural light.
Yup, it's a room, but a sunny window doesn't count as a "single, artificial light source". Perhaps showing a half finished painting might add interest to this pic.
The color of the chair (actually both the chairs) in the foreground make the whole picture appear muddier than I would like. I wonder what it would look like without them.
I may be misreading this, but there seems to be natural light coming through the window. I love the composition and feel to this shot but am not sure it meets the challenge.
Well, the challenge stated "artificial" light source and yours look like a daylight that is coming from the window.
Still, hardly a dramatic image. And although there is no way around it, using a wide angle lens inside causes right angles and straight lines to warp, as observed in this image. Sometimes it provides with dramatic effect, but in this one it subtracts from the image (in my opinion that is).
Good luck!