'Tragedy Girls,' when mean girls turn deadly mean ... but still look good on Instagram

Pitched as a “Heathers” for the Instagram age, Tyler MacIntyre’s “Tragedy Girls” lacks the satirical bite and subversive weight of that 1988 cult classic. But the movie’s central idea and bright young cast are so good that some of its shallowness is forgivable.

Brianna Hildebrand and Alexandra...