I like it, i really do. But i feel like the background makes it a little hard to see the object. Maybe make the background a little bit lighter, not nessarly a change in color, although that might do it as well if you like that.
i like how the peg's sticking out of the yang are the same color as the yin, but why don't you do the same thing for the yang holes in the yin? Make it semetricial
Also the bottom yin/yang is really hard to see because of the lighting choice you made, instead of having bright spots here and there, why not make it a centralized light source, or make it even, the light spots seem abnormal, like they were placed there randomly.
And the grey block that the yin/yang's are placed upon, what is it?it looks like a cube, although it is only one dimention.
What if you took some extra time and tryed out something kinda cool and made it 3D? Turn the grey shape into a cube, and have 4 yin/yang's on each side, then you would really be able to play with the lighting and how it affects each invidual peice.
Granted these are just some suggestions from one person opinion, but i hope they help at least in seeing things from a different point of view.
Keep up the good work, send me a message if you make a second version i would be very intrested to see what changes you will make, good luck :)