Alice Marie Johnson is making her on-camera debut, pushing Kim's new product ... and the theme is freedom. Alice talks about her experience in prison and how Kim went to war to get her out -- she calls KKW her "war angel."

Johnson says Kim's product is a metaphor for freedom ... it allows her to go to the store and pick up something she'd normally never wear, thanks to SKIMS.

Alice was sentenced to life in prison without parole in 1997 on money laundering and drug conspiracy charges ... her first offenses. Kim made headlines after meeting with President Trump, who then championed her cause and Alice was released shortly afterward.

The two developed a serious friendship ... and Alice has praised Kim's efforts ever since. This is a big moment for Kim ... she's found a way of merging her beauty brand with her social activism.

Alice's testimonial will kick off the SKIMS campaign, and we're told Kim's sisters Khloe, Kourtney, Kendall and Kylie have also all shot for the brand.