I've seen a lot on people in twitter discussing wether people should do "kinks"(?) in pride because they might scar the children for life and other arguments. Also calling people like the youtuber Big Joel pedos for thinking this is not a huge deal.
What happened? Maybe this is an american thing but since when have kids been brought to pride?
There's a specific context behind a dick pic that makes it harassment though. I don't think that the fact that it's genitals that makes it inherently wrong, it's the intent behind it, and it's the fact that you are sort of virtually putting an erect penis into someone's face expecting a response. If exposed genitals themselves are inherently wrong I don't see why flaccid penises on marble statues in a public park or museum wouldn't be considered wrong as well.
When you say "revealing them in public" it makes me think of a public flasher/predator or something and that's not how I'd personally categorize the vast majority of "near nudity" I see at pride events.