This is quite entertaining and I'm glad there are people like you, but you didn't even think it would be inappropriate to comment on a naked picture that someone receives in a private conversation? I don't even think you were supposed to look at his phone.
Yeah, you see, I don’t think you’ve quite understood the art of talking to anyone. It doesn’t happen by staring at the floor and minding your own business. Quite the opposite, mostly.
Despite illusions and every misguided attempt, when in public, you’re not actually in an impenetrable little bubble. And when your bubble bursts, you can laugh, or get angry. I recommend choosing laughter because it’s easier on the eyes.