Since the economy is struggling, the President needs positive thoughts to get through the hard time. Meaning that everyone is being abstract by thinking that the garden is a metaphor, while Chance is saying exaclty what he means. Chance does not have the same interpretation of the garden as everyone else does. This quote shows that Chance is literal and the Ambassador is figurative. Chance is being blunt, he responded in a literal way.
Chance responds in one way.
What he says is exactly what he means. He talks of the only thing that he knows, the garden. The garden is his surroundings, its his life, its who he is, its all he knows. He grew up around it. This quote proves that Chance and everyone else doesn't interpret things the same way because they both mean it in different ways.