These are some pins that just got knocked down and the pinsetter is getting ready to set
them up again for the next frame.
Pins are dropped into the brown containers that set the pins on the lane.

This is what they look like when the racks are shown. Usually there are covers over the machinery area for safety.

This is a close-up of the pins getting ready to set up for the next
ball to come in. The pins are in the rack ready to get placed on the
lane for the bowler.