I guess it's wrong to do something different from the reference?

compared to the reference, you've given the figure a shorter torso (especially bellybutton-to-pelvis length. look at the distance between the 'V' of the pubic area and the belly button in both images.) The arms are also short, partly because the torso is truncated, but also because they're just too short. torso length aside, the reference has the wrist nearly at the level of the bottom of the pelvis. the neck is also a little shorter and the head off-center to our left. the hips have also been simplified a lot, pay attention to negative space and the gentle curves near where the arm and hip meet on our left. the back doesn't maintain the same arch as the ref, which makes the upper torso look shorter than it should be.

main thing to do here is measure the individual parts in relation to each other. see where key areas align on horizontal or vertical axes, the distance between forms, their sizes relative to one another, negative space, etc. but also think about more general things like the gesture of the pose and the curve of the spine, that adds a lot of character to a pose.

thanks, i understand it better now :)  i also think the right arm is a bit funky though.  looks broken at the wrist.  i'd work  on bringing the forearm more foreweard in space

Yes, the pose is a bit weird, I used this as reference. (NSFW too obviously)

Probably has boobs. Very likely even.

most ironic use of a nsfw tag I've seen in a while

more AA on the outline would have been great, but apart from that, lovely piece

might wanna put nudity or smth in your title for the more sensitive people

i think there are some pose/ anatomy issues.  I think youre trying to depict her body not completely in portrait view, but with her right side slightly towards us?   Since she is almost head on with the viewpoint then, her left breast would not be rotated that much.  

One reason I was kinda confused whether she is just slightly turned or whether she is just shifting weight to her left side is the lighting.  The head depicts shows the light source is hitting her top left, yet her left side is tilting slightly away from us, so the two kind of cancel each other out.  The fact the body is slightly rotated makes it more confusing, since at first I thought she was shifting weight to her left side and then the hips needed to be flipped. 

If she is indeed just rotating her right side slightly towards us then, I think the perspective of the breasts need to be fixed, and perhaps shifting the light source to her top right instead, so you can derive a stronger contrast in the lighting to better represent her pose and forms, since you put the light source to the side that is tilting away from us.

...or maybe the problem is that the head arms and neck are more at a head on perspective, while the body is slightly rotated :S

She's intense. And pretty! I like the realistic shading on her stomach.