Snapchat added a new filter inspired by anime cartoons. However, many people immediately saw this as an ugly example of yellowface.
Everyone knows the best part about Snapchat is the filters. But a new filter was added that many people found offensive. "Yellowface" is when a non-Asian person dresses up or uses makeup (or in this case, a filter) to create cartoonish exaggeration of stereotypical Asian features – it's considered offensive in the same way blackface is.
Snapchat told The Verge that the filter was "inspired by anime and meant to be playful." The filter has been taken out of rotation due to the response.