I've been scolded for taking pictures of big wins both hand pays. One in Washington state where I live and one in Oregon. Both times they tried to play the "state law" line which I called BS on and asked to see proof of state law, which they couldn't provide since it doesn't exist in either state.
I then said I'm only taking a picture of my hit and am NOT filming or taking pictures of any person in the casino as I wouldn't want my picture taken in a casino without my permission and, said "besides,'I'm going to show my friends my big hit, at your casino, so look at it as free advertising".... The guy in Oregon said "you kind of have a point" and dropped it.
While the lady at my local kept going and in front of payout personnel I said if this discussion continues you will be forfeiting any tips that I was going to give your employees, she then quickly dropped the subject.