What the excerpt is trying to convey is that, with the current generation we are so preoccupied with own self-interests. We value vanity, self and glory without considering the individuals we face as we walk, as we talk and as we engage. The passage reinstates that individuals have to get back and introspect about not their own gratifications and egotistical desires but the welfare with others, even though it is innate and inevitable that we always point to the ego.
If anyone still wants to know what the answer is it should be : "Nosy implies that Emma has ulterior motives for asking about Jack’s project; curious implies that she is genuinely interested."
