The brake light switch is the item below the circle in the picture.
The item with the rubber hose is a vacuum dump for the cruise control servo. When you step on the brake, the valve opens and vents the cruise vacuum servo to atmosphere, releasing the throttle. Its a Hail Mary in case EEC doesn't see the BOO (Brake On-Off) and release the cruise electrically as its supposed to. Its not unusual for the brake light switch to fail, and EEC looks at the BOO circuit to cancel cruise when the pedal is pressed. So if BOO was bad, cruise wouldn't cancel via EEC, but the vacuum dump valve would at least release the throttle.
Your '93 doesn't have a vacuum dump valve because it has an electric cruise servo.
Gary Morrell
Edited for clarity.