Mm. Yeah, there's a line, but it's very fuzzy and hard to pin down, and your mileage will vary for any given example. I tend to find reading chain restaurant menus an exercise in pretension (fancy language dressing up far-less amazing food items), but just describing the sensory qualities of food in artsy language is often the best way to say what you actually mean -- aesthetics can totally cross disciplines like that.
I have a strategy for getting myself to eat vegetables. I've been using it for about six months now, and it works well:
Side effect: people who see my plate think I'm a very healthy eater. But sometimes they ask my "why is your salad steaming?"
I also posted this on my blog