Sounds like a storm in a teacup to me. Firstly, if the woman was unaware of what was going on, then the last thing anybody should do is tell her, why cause her an upset for nothing? That assumes she would have been upset, which may not have been the case. If she was doing it in public, she would expect people to look. In addtion in some places, including NY, (I’m assuming you are in the US,) then women are allowed to go around bare breasted anyway, if they so choose.
Secondly, if she was doing it in public, then anyvbody may to take pictures, just as they can do of any other event in public. It there was a notice up saying no picture taking of clients, then that would be different.
Being as the police turned up, they notice everything that goes on in their vicinity, thts what they are trained to do, and it becomes a habit, even off duty, it was upto them to take action if they thought there was an offence being commited.
Just because you didn’t agree with it, its still not upto you to cause a problem on other peoples behalf, its usually termed being a busybody. IF they complain, then you can help them out