Well until you find a way to give samples for taste and smell to your mobile users (good luck with that), I think that the visual side is what's left of it.
Even tho I agree with lots of other folks here about the fact that choosing a restaurant might require more data than just a couple nice pictures... as far as food itself go, a picture is what describes it best (worth a thousand words they say).
I cringed when I read that phrase. What about smell? are you going to eat food that looks great but smells bad?
The visual aspect of food is highly overrated, it mostly stems from pretentious restaurants that emphasis the importance of presentation.
I agree that food is visual, but other senses such as smell, texture are equally, if not more important than the visual aspect.
The idea for this application is not new and it seems to be only available for iOS (I'm on Android) only so I don't have much to say about it. When I want to find a nice place to eat food, word of mouth from friends or colleagues is what I use.