The aliens are only mentioned in dialogue or seen through the Wall in the background.
During the Duke's opening speech, a playing card belonging to the Incredible Burn Victim Trash Man can be seen in the casino area.
Terry's shirt in this episode is "sample text". It is only seen in the background of the wall.
The title is a complete misnomer as Terry and Korvo are only viewed through the glass of the wall in this episode. The stealing of a bear isn't seen.
This episode is set completely within the wall of miniaturized humans.