Walk away. There's nothing they can do to you legally bc taking pictures in public is completely legal anyway. There's nothing you can do to them legally bc yelling at you is completely legal. You probably can't talk this person down bc they're probably suffering some kind of mental health problem. So all you can really do is walk away.
Odds are nobody else is going to do anything to you, but if they get too close, just start filming in case you need evidence later for a lawsuit.
Look! Look! Look at the pictures on my phone. See? No feet. Not a one. Well, there's that one, but that's my foot — I was just checking a callus I couldn't see well. But certainly, there's no pictures of your feet here.