The pope, more than likely, practiced a very mild form of self-flagellation during prayer. It is not as extreme as many believe it to be.
Those who try to make a bigger issue out of it are just using it as a pretext to attack the Catholic church. Bigots, all of them.
I address this to no one but myself but for everyone who has read this thread or others like it.Do not attempt this without a spiritual director.Not all self mortification is for your sins,some are for your Highs and to bring you down to earth.Always talk to your spiritual director. for mortifications.