Texture
I think movement is quite mathematical. You can describe it: moving from one set of coordinates to another, or rotating through a certain angle. But when I ask myself whether that is all I like, the answer is no. Texture matters, too.
Texture is not just roughness, noise, or grain. Movement has texture, too. I do not really know yet what textures I like, but I think it is a matter of taste, or a shared language that holds a whole series together.
Maybe it could be put into words or given numerical values, but that feels like a hassle. I think creating that texture is very much a human task. The individual touch seems to lie in what kind of texture you give to the core of a piece.