Twitter's image-cropping algorithm prefers to show faces that are younger, slimmer and with light skin tone, a researcher has found.
Bogdan Kulynyc won $3,500 in a contest organised by Twitter to find biases in its cropping algorithm.
Earlier Twitter's own research found that the algorithm had a bias towards cropping out black faces.
When two faces were in the same image users discovered, that the preview crop appeared to favour white faces, hiding the black faces until users clicked through.