Robin is eating an ice-cream cone in Ted's new car, the ice-cream is dripping down the cone. In the next shot of her the ice-cream isn't dripping at all.
At the beginning of the episode we hear Barney's voice saying, "Ted, this is New York City..." but we actually see Lily's mouth moving (Barney is not initially in the shot and the J-Cut replaces Lily's dialogue so that Lily's mouth moves but she says nothing).