Did you or them undo the ally burner ring ? I see they were nice enough to put the retaining bolt back l in place ..
Kind of reminds me of a couple of nice Dutch / German backpacker girls set up camp beside us on Fraser one year, sitting a cook pot on the top ring Grab handle of a 4.5 Kg gas bottle, turning the gas tap on and lighting it ..
They couldnt work out why I got a bit excitable and turned it off on them, They had been trying to heat up noodles like this for a couple of days ..
Digging around in their gear we found the burner that was supposed to screw onto the gas bottle and set it up for them, They were amazed at how quick it heated up their food .