The Watcher Gun Emplacement is the Watcher equivalent of the human stationary turret. It is suicide to attack from the front due to its rapid-fire capabilities and shield (unless you are using a Reclaimer to snipe through the viewhole in the front), so in most situations you should flank it using your rocket pack and take out the gunner instead.

The versions the player gets to control in the game do not have shields, and it is unknown as to why this is.