When you look at any physical product, it is generally co-developed by a cross-functional team including industrial designers (who decide on the form and function, and take human factors and ergonomics into consideration) and engineers (which can span mechanical, electrical and software engineers depending on the product and its feature set). The cosmetic and tactile presentation of the product in the form of texture, fit, finish and color choices are important factors that come in later in the game and are also considerations that the industrial designer weighs in.
Contrary to common misconceptions (most frequently embraced by engineers), the job of the industrial designer is not to "make things pretty". Their primary mission is to create easy to use products that serve the function they are designed for while pleasing the end user. It is a complex discipline that is taught by schools like Rhode Island School of Design, Cleveland School of Art and Design, Cooper Union, Design School of Palo Alto and the like.