In China, the photo app Meitu is a go-to tool for retouching selfies. Its cutesy filters—think petals, pearly skin, and dramatic blush—have long been staples of social-media feeds in China. It’s only ...

If you’ve spent more than a few minutes on Twitter or Instagram in the past few days, you’ve seen it at work: a filter that renders your face in the style of Japanese anime in real-time. The trend has ...