I recently posted a video with three different thumbnails in order to test which thumbnail is the best. Most of the time when I do this, the test is somewhat meaningless. All three thumbnails perform largely the same. In this case, interestingly, there IS a small difference.
Two of the thumbnails feature pictures of me and the people I had brunch with. But the other thumbnail is simply a picture of a plate of Indonesian food. And that food thumbnail scored 26.8% while the thumbnails with pictures of people scored 36% and 37%. It’s not a huge difference, but it does indicate that people prefer thumbnails with people in them.
For more meaningful results, I should have used just two thumbnails: one with food and one with people. I wonder what the split would have been had I done that?