This moment seems to reveal Nick's developing cynicism, contrasted with Gatsby's seemingly eternal optimism. One of the last things Gatsby said to Nick was, "'I suppose Daisy'll call too.' He looked at [Nick] anxiously, as if he hoped [Nick would] corroborate this." Nick wasn't sure then that she would, and he later attributes his doubt to Gatsby. He says,
I have an idea that Gatsby himself didn't believe [the call] would come, and perhaps he no longer cared. If that was true he must have felt that he had lost the old warm world, paid a high price for living too long with a single dream.
It seems completely unlike Gatsby to no longer care about whether or not Daisy calls. He has done everything in order to be permanently reunited with her, and it seems that he would do absolutely anything for her, including taking the blame for the death of Myrtle Wilson, who Daisy hit and killed with Gatsby's car. How could he no longer care? It must be Nick who no longer cares if it works about between Gatsby and Daisy because, as he said to Gatsby earlier, "'They're a rotten crowd [...]. You're worth the whole damn bunch put together.'" It isn't Gatsby who has given up on Daisy but, rather, Nick who has given up on everyone but Gatsby. Gatsby has always been capable of keeping his dream alive, of not losing his childlike innocence, something at which Nick has not been as successful; his disillusionment after the war is what brought him to New York in the first place.
Ultimately, then, I think we are supposed to find Gatsby to be more attractive than Nick. Gatsby's "romantic readiness," an optimism and dreaminess that makes him "gorgeous," is what Nick admires and even loves about him, and Gatsby is able to hold on to these qualities until the last, and this makes him, as the title claims, truly "Great."