Roger's set up The Gun to open a portal to a different universe - a portal that's about 10 feet above the surface of an exploding Class 'O' sun, and the radiation is peeling the paint off the corridor walls while the robots are being converted back into their component ores....
(Roger and Jinx went sideways from the corridor the robots were in, and they appear to be almost off-shot to the right of the current scene.)
Of course, the button may simply have fired The Mother Of All Lasers (remember all those big electrical thingees Roger ran past?) down the corridor for the same effect.
Hope Swampy didn't just stick his head out the door to see what all the racket in the hallway was about!