Anticipating his meeting with Daisy takes an emotional toll on Gatsby. He goes to great lengths to make certain that all is prepared for her appearance--the grass being cut, the flowers being delivered, the food being suitable. The day of the meeting, Gatsby is quite pale; the dark circles under his eyes indicate that he has not slept. He is concerned that it is raining, but has checked the paper to see when it might stop.
As the time grows nearer to Daisy's arrival, he decides suddenly to go home. When Nick makes him stay, he sits back down "miserably." The stress of meeting Daisy again is enormous for him. When Daisy arrives and Nick escorts her into the house, Gatsby has disappeared, having gone out the back door. He returns and knocks on the front door:
Gatsby, pale as death, with his hands plunged like weights in his coat pockets, was standing in a puddle of water glaring tragically into my eyes.
The next time Nick sees Gatsby, in the living room with Daisy, Gatsby has assumed a casual air, leaning against the mantle of the fireplace. His nervousness is obvious, though, because he leans so far back that his head comes into contact with the clock on the mantle, almost knocking it to the floor. Gatsby's fingers tremble as he catches it. Talking with Nick alone a moment later, he despairs that having Daisy come over has been "a terrible, terrible mistake." Nick leaves Gatsby alone with Daisy.
When seen again, Gatsby's manner has changed dramatically. All his embarrassment is gone. Nick says he "literally glowed" and "a new well-being radiated from him." Gatsby smiles and becomes filled with enthusiasm.