Pacing back and forth with George, Harry Bentley bumps into the cabinet, knocking over plates that were inside. A few seconds later, the plates are right back up again.
Early in the episode Louise says she is taking Mr. Bentley's plant into the kitchen where it can get more sunlight. The Jefferson's kitchen had no window. (Note: There is a small window in the kitchen - located on the same wall along the terrace (on the characters' right when entering the kitchen). Usually the window is shuttered up).