The view out the plane's windows are either a brownish landscape when on the ground in Pixley or a blue sky with passing wisps of cloud. However, when the stewardess is saying that Arnold isn't allowed on the plane, the close-up of Arnold shows the blue sky and passing cloud background, even though the plane hasn't yet left the ground.
In a closeup when Arnold is sitting at the bar, you can see the trainers fingers touching his belly, making Arnold grunt and move.