To be blunt, the design of mobile devices is incredibly limited these days. The front is glass and 95% screen, the button placement has been dictated by years of legacy (and the couple of people who’ve tried distinct and new things like buttons on the back have usually eaten dirt because of it). The sides are only a couple MM thin so you’re very limited.
Samsung’s main innovation was actually getting the screen to take on some new shape, which leads to an interesting design and improves the feeling in the hand, but has limited novelty outside of that.
It’s a very stagnant industry because of that, and it means there are simply very limited design opportunities, even for professionals.
If you purely wanted to improve this presentation, I’d consider polishing up some of the renders, add some materials for things like the case so they feel more thought out. But as an overall design exercise mobile devices are incredibly hard, don’t take it as a strike against your work.
Now redesigning the Hololens, THAT would be a great design exercise. 