The "Observer" appears on the security monitor at the beginning of the episode.
The glyphs in this episode spell "Trade".
One of the bank robbers wants to know what they have been stealing and is shown an olive green gizmo that he thinks might be a camera. It is actually a Wild Heerbrugg brand theodolite, probably from after 1950. Theodolites are used mostly in surveying to measure vertical and horizontal angles with great precision.
The license plate number of the van used by the thieves is 1R2D21.
The toy that Walter vibrates through the rice is a G.I. Joe Slip-Stream action figure, released with the Conquest X-30 jet in 1986.