Not my idea but having made the slomo I can better see what is happening. One screenshot could show just the two lights, which I suspect are for the crew connecting the aircraft nosewheel via the hold back to the catapult shuttle. Another screenshot would show the chap on the left who goes over to pick up what is left of that holdback fitting (highlighted in the light) whilst two others on the right start to go over to do what they do. Others not concerned because there is no fire - just an illusion.
'Engines' replied as I typed.... Yes - with fast action the chaps going over - particularly the first one - had me fooled but now I think the evidence is clear.
There is a slo mo of a day catapult here: (one can see the big hunk 0'change wot is left behind)