Psychology. You watch the picture as a whole and the face is also as important as any other part of the body. On a single picture it's not alive, sure the whole person is on that, but it's different when it comes to videos.
Videos are much closer to the reality than a single picture and you read not only the body, but also the ever changing facial expressions. Faces are much more important to us than you would think. We are built to recognize an other person by their faces and we read the faces on a subconscious level.
The face of a woman adds much more to the content than only the body or it's parts, be it a breast or a pussy. Sure, you can see her softer video content with face and the more revealing without face, but the entire experience becomes a whole with the face.
This is the case with any other sex videos, more likely with those "leaked" celebrity ones. Most of them doesn't contain the face because of the reason above: they hold you back from having the whole experience, the whole fulfillment, so they keep up the interest, you want more.
Videos are much closer to the reality than a single picture and you read not only the body, but also the ever changing facial expressions. Faces are much more important to us than you would think. We are built to recognize an other person by their faces and we read the faces on a subconscious level.
The face of a woman adds much more to the content than only the body or it's parts, be it a breast or a pussy. Sure, you can see her softer video content with face and the more revealing without face, but the entire experience becomes a whole with the face.
This is the case with any other sex videos, more likely with those "leaked" celebrity ones. Most of them doesn't contain the face because of the reason above: they hold you back from having the whole experience, the whole fulfillment, so they keep up the interest, you want more.