I did watch the video - there was no explanation for the knee. Also, the logic he utilized for the streak that appeared on the left side of the grandfather’s shoulder doesn’t hold much water with me. You don’t add an image to a portion of the photo you are editing and ‘drag’ it to the final location of the image - using transparency or layers during the edit would not produce such an effect.
Knee looks like a shadow to me. Problem is Obama not wnd.
More controversy w/ everything he says and does than all former presidents combined.
If the photoshop user is a rank amateur you do.