One may not need be an artist, per se, but one would certainly need a number of skills. Personally I would never create something like your example as a 2D illustration since I don't have that skill, but I would approach it as a 3D model. As such, proficiency with CAD would be required. One would do a number of renders - at least two (a render of everything but the body and a render of only the body). Next it would need a lot of post render work which could be done in Photoshop. Again, a proficient level of skill would be required using Photoshop. As in the example above, one would layer the renders and then erase and feather the cutouts on the body layer which resides on top and reveals the workings underneath. This is a simplified explanation and approach, but it would be something along that line. As such technical skill would be the most relevant requirement. And artistry in the sense that one would need to have a vision of what they want to produce.