As her dead seven-year-old boy's face appeared on screen at Sydney's Supreme Court, Kayla James began crying.
In the video from March 2013, James is recorded drilling her son about "wetting his pants".
Calling him a "little s***", she adds "You don't talk to me like a piece of s***".
"Yes Mum," he replies.
When crown prosecutor Chris Maxwell QC asked James how she felt watching that, she replied through tears: "Disgusted, so disgusted".
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James is currently serving a prison term of at least 10 years and six months for 11 offences, including the manslaughter of her son, who cannot be named, after she failed to seek medical attention.
Kodi Maybir, meanwhile, has pleaded guilty to his manslaughter on the basis of criminal negligence but denies crown allegations he murdered the boy by inflicting the fatal injuries.
Speaking at his trial on Monday, James said she became "intimate" with Maybir almost immediately after meeting him in January 2013 and within two weeks moved into the Christian hip hop producer's music studio in Oatley in Sydney's south.
By May 21, 2013, her eldest son was dead.
Before she met Maybir, James says she looked after her three children very well.
"I was loving, kind," she said.
Discipline at this point, she said, consisted of timeouts and the occasional smack on the back of their hands.
"After Mr Maybir I became distant ... I was doubting myself as a parent. I was told that my parenting skills were inadequate by Mr Maybir.
"He explained to me that I wasn't as firm as I should be. That I allow my children to manipulate me emotionally."
Maybir, she told the court, was "inspired" by the Spartan film 300 as he believed it portrayed "great obedience".
She said he instituted a variety of punishments, including smacking her children's feet with the heel of a shoe, make them punch one another and get them to do squats.
In love, James said she tried to become the woman she thought he wanted her to be.
"He (Maybir) would talk to me about his ex-wife and two children and how he wanted to meet a woman who loved him more than he loved her and how obedient she needed to be," Ms James told the court.
"I wanted to be anything he wanted me to be."
The court has previously heard that when emergency services came to the studio on May 21, 2013 to help the boy, Maybir told them he had fallen off a pogo stick.
After the boy's death, the court heard, his body showed a litany of old injuries, including fractures to the ribs, left foot and a finger, and linear marks on his hands and buttocks.
The trial continues.
