At around 39:00, Emily, Richard, and Rory are standing in a group and then move off in separate directions before Lorelai shouts and brings them up short. The actors clearly anticipate this stop, especially Emily, who walks quite slowly in order to stay in the shot and fully stops before Lorelai's shout.
In the flower market scene, Sookie and Lorelai have green tape on their costumes, ostensibly marked for the scene.