Largo's screen still has Domo-kun on it, this time he is doing the badger dance from the "Badgers Badgers Mushroom" flash animation that was the internet fad du jour when this strip was drawn.
thr347 = threat
What is the background of the third panel?
actually, that is a door. its a large opening in on of the buildings across the way (those are pipe barriers on each side of it). All of this is happening on a dock, which is about 3 feet off the ground.
Any lack of clarity in understanding that is my fault ^^;;