"Undressing my Mother" Disturbing, but for Unexpected Reasons

Upon watching "Undressing my Mother", I was fully prepared to see an old overweight woman in the nude. I have, after all, seen The Shining dozens of times, and anyone who has seen it is surely desensitized to grotesque nude old women. While the context of the two images are completely different, and intended to evoke different thoughts and emotions, I do find it true that any cultured person in today's world is somewhat desensitized to the spectacle of a grotesque nude image. That being said, the image of the nude old lady alone was not enough to make me squirm.
This video was so oddly captivating for me that I felt as though I had to show a female friend of mine to see what she thought, as I thought a feminine perspective on questions of beauty and the body would be different than mine, or at least more empathetic to the old woman (not that she is ugly, but I do believe she would value the feeling of being sexy more than, say, me). I almost feel like it would be difficult to have a meaningful discussion without involving women, or at least a strong feminine presence. I am not trying to say the woman I talked to represents the entire female gender, but she did help to clarify things from a feminine point of view.
She said essentially the same things I did about it, but I think she was more put off by different things than me. For me, I was mostly put off by not the images, but her descriptions of herself, and how they contributed to her self image. Her description of her bottom, as "two cheeks with a hole in the middle" provokes an uncomfortable laugh, but the laugh for me came only from trying to shake off the awkwardness of having an old woman describe her most intimate parts. Also, she seemed so unashamed of her body, as if she were just getting out of the shower and looking at herself in the mirror as if no one were watching was off putting for me. I felt like a fly on the wall who had no business seeing what I saw.
The girl who I talked to was off put by just how undressed she was. Certainly in the literal sense, but also in the figurative sense. She was amazed that she was able to do this in front of her son more than she was amazed that she would do it in front of an audience of millions of internet users. She did naturally feel a sense of empowerment in how she defined beauty for herself, and defined her sense of sexiness by the only person whose opinion mattered to her, her husband. But at the same time, she felt the feeling she got from her husband could not be communicated without a sense of grotesque, because it came from a personal connection which no one else was a part of, and to invite anyone else in on the same appreciation would take away from the special connection she had with her husband.