When Jerry and George talk in the apartment while Jerry reads the newspaper, a blue glass on the table moves around between shots.
When in Jerry's (Jerry Seinfeld) apartment, Elaine (Julia Louis-Dreyfus) crushes an empty beer can on the kitchen counter and leaves. In the next shot we see a different can on the bench.
Elaine crushes the beer can on the counter. In the next shot, it's on the cutting board. It also wobbles on the cutting board even though no one has touched it.
As Kramer leaves the coffee shop Jerry is waiting and leaning against a parking meter. As Jerry walks away the parking meter wobbles.