It's both the focus and the sharpness of colors that make this shot so beautiful. The only weakness this picture has might be the balance and the framing. It is so busy in the lower left corner that it's hard to look at it as a whole. Overall I'd say that if you had taken a number of pics of this with different framing for each you might have found one with a more pleasing balance. Please keep in mind that it is a beautiful picture regardless of whether or not it could be improved.