A redheaded elf in an exercise outfit and sporting a VERY secure ball gag...plus the spreader bar and a strict harness tie holding her place? GodDAMN this is cute, the fact that I prefer tape gags has nothing on the fetishistic fantasticness you've drawn here.
I love how the elf girl's hands seem to be resting on her, as her breasts bulge between the ropes; being tied so strictly like this would serve as a challenge when the vibrator is turned on, only for her every move to cause the ropes to dig a little deeper.
Freeman3 made a great choice with this commish, and your rendition of it in all its visual glory is just...well, another sight to behold! I know the finished version of this already got posted to dA, but just wanted to comment here now.