Katy Perry’s undeniably a pop star, but she’s not really a Pop Star with all those Capital Letters. Sure, she’s got her hordes of fans and sells gazillion albums, but what even really is her identity?

The collection opens with her smash hit “Roar,” which features a grand-scale production, with dancers and acrobats, that is reminiscent of a quintessential Madonna concert, as well as vibrant laser ...