He looked out the window at it, but judging from his expression I don’t believe he saw a thing.
Moments before Daisy’s arrival, there’s nothing left to prepare. The grass has been cut, the cottage has been stocked with tea and cakes and a greenhouse of flowers. Gatsby is elegant, casual, perfectly tailored and utterly petrified. He can’t see; light enters his eye, draws on his retinas, but his brain isn’t really putting together the images.
The moment before the big moment is always excruciating and beautiful. Glorious success or crushing defeat could be seconds away, and this moment before is a quantum state where both are present at the same time, both so real that the mind and body experience both elation and desolation at once.