TellSpec: hand-held device that tells you allergens/calories/ingredients of food

The technology seems interesting, even though they say the device is only a model (not even a prototype) and the mobile app is clearly just screen mockups.

It seems like you should be able to use a spectrometer to get chemical content from food, and thus ingredients, but I'm not clear on how you can calculate calories or nutrition.

I wonder if it works on Soylent? ;)