It finally hit me! It isn't, as I conjectured in February, that the "policemen" were staring a circus to cheer up the poor Palestinian Arab children and alleviate the humanitarian crisis.
But the real answer can be seen in another picture, variants of which have been published many dozens of times (כן ירבו):
Notice the relative sizes of the flaming hoops and the burnt out car window.
Palestinian Arab "police" are pursuing a skill that is very practical and much in demand in the territories: they need to practice quickly jumping out of the windows of flaming cars!