Before Chloe, Paris, October 2015. 
A magazine was doing a photoshoot during one day of fashion week — these were the models. I think there has been one of these "things" during every season of PFW since I have been going (last season was the model who kept flashing everyone... which was memorable!). I guess if you want to shoot in a crowd with loads of people holding cameras, it is an ideal (and no-budget!) environment.