from a visual standpoint i think your sketch style is nice, clean and simple. Which translates into what your design is also trying to communicate. Many designers forget that the style of the sketch plays a big role. i.e going for sophisticated but yet the sketch is more suited for toy development.
I do believe that a sketch should speak for its self, but at the core it is an inanimate object that needs you to provide the voice and thus when you are not present the sketch should clearly communicate the what, why and how. As well as communicate Why this is better then what exists already for the user. If it is purely a styling and sketching exercise then i think you nailed it. if it is meant to be a designed product then you need to show more of the why behind your design.