Do you share embarrassing photos of your kids online?

I’m having trouble understanding why so many parents do this. Especially one of my relatives, who has a three-year-old – she’ll post photos of his bare butt, him naked in the bathtub, crying in all sorts of different situations, and even one of him squatting on the floor “moments before taking a dump, stepping in it and running off screaming,” which was related with apparent glee. Won’t this embarrass him as he gets older? Is it some kind of important parental bonding thing to share stuff like this? Am I overreacting, and this is not weird, disgusting, and attention-seeking behavior but a harmless bit of fun?