We were asked to design a companion, or pesky little brother, to R2 named DD-3. He would belong to a new alien race that joins the Alliance. I developed some ideas that were a little more streamlined and pushed the late-70's-early 80's design aesthetic, but decided to reign it back in to be in the same vein as R2's model. I assumed that R2's design would be distributed around the galaxy.
I gave DD-3 the traditional rule-of-thirds proportions (basically a baby), and added a scrawny neck so his dome could pop up and give him more articulation and personality with curious head movements. The "awww" moments when a puppy or kitten cocks their head sideways.