Millions have watched the shocking tape, which first surfaced weeks after Smith's death 10 years ago this month from a drug overdose. In the video, Smith looked bewildered and out of it.
"She was not in her right state of mind and I look back and realize that," Ryley Shelley, now 19, told Inside Edition.
Shelley is studying pre-med at the University of South Carolina. She got to know Smith because her parents were friends with the doomed star.
Smith used to come and visit the then-9-year-old in Myrtle Beach, South Carolina, where they would spend time together celebrating birthdays and holidays. She said their relationship was like a big sister and little sister.
Shelley described the former Playmate of the Year as "an amazing woman."
"She was patient with me," she said. "I was annoying, I know for a fact I was annoying. She loved me anyway."
The clown video was actually shot in the Bahamas, where the girl's parents own a beautiful home. It was Shelley's ninth birthday.
Shelley recalled: "I loved doing makeup and she let me do her face."
The two were copying the image they found on the front of a clown makeup kit. Even at 9, she instinctively knew something was wrong with Smith.
In the video, Shelley was recorded saying that Smith "has brain trouble."
Shelley now looks back on that day, saying: "I was scared that it was not the Anna I knew."
When the video was made, Smith was pregnant with her daughter, Dannielynn.
In one of the most shocking moments, Smith, who appeared high, may have forgotten she was pregnant.
"I think I am having some gas trouble," Smith declared.
Shelley tried to bring her back to reality, saying: "That's your baby kicking."
Smith then spotted a doll by the pool and might have thought it was her child, saying in the video: "My baby's over there."
The young girl wanted to take the batteries out to prove it was a doll and as she tried to pull out a panel where the batteries would go, Smith got upset because she believed Shelley was hurting her newborn.
"Don't tear her skin open," Smith said.
Now, Shelley said, "She gave it so much love and attention and I was just confused."
The teenager now says she is disappointed Smith never got the help that she needed.
"It breaks my heart and makes me angry. I wonder what more could have a 9-year-old done more. I don't think I could have done more and that is what scares me. I did all I could and it wasn't enough," she said.