They apparently did a pretty large scale test to decide if a video performs better when the mouth ist open or closed. Open mouth performed so much better that they even retroactively photoshopped their old videos thumbnails to add a open mouth smile to them. That might also contribute to them appearing creepy since they only changed the mouth.
They apparently did a pretty large scale test to decide if a video performs better when the mouth ist open or closed. Open mouth performed so much better that they even retroactively photoshopped their old videos thumbnails to add a open mouth smile to them. That might also contribute to them appearing creepy since they only changed the mouth.