Indeed. And when you give it just a moment of thought, you have to believe the photo wasn't just a "one and done," serendipitously catching mom and baby in the middle of a feeding. This was a professional shoot, with the proper lighting and angles to the subject. The young boy was undoubtedly "coached" on how much of the breast to take into his mouth (lest any nipple or areola be shown), and what angle to look at the camera. There were likely multiple photos in order to get, "just the right shot." This was anything but a beautiful moment of intimacy between mother and child, captured on film.
I am tempted to respond to your post with, “Well, duh”, but I suspect a lot of people have not thought of that and it needs to be said. This is clearly part of a photo shoot. There are probably hundreds of shots. Everything from on the couch to sitting to you name it. Probably even some with her partially nude.