Draw both theoretical bodies fully. Not just the outer outlines. Then draw the motion lines between them. Thats your problem. Well not so much a problem, but a testicular issue
Seconding what Frag said. Notice how in those two links there's overlapping lines, which gives off the illusion of motion, whereas in yours, it looks like the two ends are one lump of testicular thingamabob, not one part wiggling in motion. It's all about the overlapping lines, mate.
I still don't like your font choice, though (lol), but I guess that fits well with the Walfas-ish art style? Whatever works, I guess~