As previously established, Black Widow’s opening credits sequence offers a glimpse into how Natasha Romanoff and other young girls like her are made into Widows. The process involves everything from training with weapons, lessons in ballet dancing, and even watching violent Disney cartoons, which appears to be one of the Red Room’s methods of psychological manipulation. As Yelena Belova points out to her adoptive sister at one point, she and other were not manipulated psychologically, but surgically.
The credits present close-ups of the young Widows being prepped for what is essentially a lobotomy that can only be reversed with an antidote that cures Yelena while she is on a mission to repossess it. This is preceded by squealing pigs, which foreshadows Melina’s mind control demonstration, symbolizes how the Red Room perceives these helpless young women, and briefly adds a tone to Black Widow that is reminiscent of horror movies like the Saw franchise. Indeed, this is easily the most horrifying moment in already thoroughly depressing sequence.
Article source: https://www.cinemablend.com/news/2570451/black-widows-opening-credits-a-closer-look-at-that-smells-like-teen-spirit-sequence