Proportions are wrong (arm is too long), her middle fingers are ridiculously long and red, and you can faintly see what is either a mannequin join above the wrist, or a lazy photoshop job where they haven’t quite colourmatched the skin correctly.
Either way, it should have been edited to look better, not like this!
It’s not the upper arm that’s the give away, anyway. Some far eastern women do have very slight frames.