There are a few things weird about this phone. First, if we were to design a cellphone to smell foods and keep track of your diet, we probably wouldn't design it like an avocado. Second, on the off chance that we were to design it like an avocado, we probably wouldn't make it an avocado with a bite taken out of it. But that's just us.
The idea itself—keeping track of what types of foods you've eaten by its chemical signature and telling you what foods you're lacking—is pretty sound. Why not just integrate it into a regular-looking phone?