It's a reaction to Muslim culture. It may be unfair, it may be wrongheaded, it may even be illegal, but it's not racism.
The Nuns aren't being banned from wearing full habits to the beach because they are Catholic not because they are "European" or "White" There are swarthy skinned nuns, some of who might even be Christian Arabs who are not going to have a run-in with the police at the beach.
It's prejudicial and discriminatory for sure, and I think it's stupid and ultimately unnecessary. I think the officials in these cities are doing it so they can show voters they are doing "something" about the "threat" of Muslim terrorism. I bet it's pretty popular where it is in place. Doesn't make it right of course but it's a reason why politicians do things that are wrong.
They aren't singling out Arabs, they are singling out Muslims.
It's as if "racism" is the worst thing in the world that anyone can be charged with and if the charge sticks, there are some special consequences that follow.
Prejudicial discrimination based on religion and/or culture is bad enough, and, in this case, far more accurate than racism.