The “faces” used in these tests (not just this video) look very exaggerated and “phony” to me. I don’t perceive an “emotion” but instead begin to wonder whether the unnatural faces promote “cheating” in the test subject. That is, are people really good at deciphering faces, or are the tests designed to make the task easier?
Also, the faces are static and without context. Human faces / emotions are not static and expression is fluid. This type of test is not realistic. So what does it mean?
Also, how would one identify “disgust” (or other emotion) if one hadn’t named it “disgust” and taught people that this particular face matches the emotion named “disgust” ? Animals don’t have words for emotions, but they express emotion / “reactions” to the environment.