Early on in the movie, which comes out on DVD May 1, three months after Smith's death, there's a clip from Smith's reality-TV show in which she devours a life-size cake made in her own image.
"Eating her own image, that's what she does in the movie," said David Giancola, director of "Illegal Aliens," on which Smith was a producer and her late son, Daniel Smith, was associate producer. "She really wanted people to laugh. Anna and Daniel wanted to make a movie that satirized Hollywood and ourselves to a great extent."
An opening scene shows the trio of shape-shifting visitors coming to Earth, Soren and Jimenez's characters shaped like alien blobs and Smith's shaped like a hog, accompanied by her little-girl voice squealing, "I'm a pig in space!" They later transform into hot women and get jobs as stunt experts in Hollywood.
In one scene, Smith's Lucy is scolded by Cameron to put on more clothes, a reference to the revealing outfits for which the Playboy Playmate of the Year was known.
Smith plays Lucy as an extreme parody of her own ditzy-blonde image, providing the movie's bumbling comic relief while Soren and Jimenez do the heavy lifting on the action scenes.
"She was always wanting to go the extra mile to do the spit-takes, do the falls, be silly. She really let her child-self out; that little kid in everyone," Soren said. "It gave us permission to have more fun and be silly, because the movie's silly. ...
"She just had an innocence about her. Some people may call it ditzy, but I tend to call it an innocence. Even through all of her life's ups and downs she experienced, she tended to keep this innocence and this big spirit. That's part of who she was and what her charm was."
Lucy passes the time by coloring with crayons, has puzzling moments trying to figure out what a sexual aid is for and mistakenly refers to Syntax, the aliens' computer overseer, as Charlie, another "Angels" gag.
Smith is shown snoring loudly on a couch while her colleagues keep their nemesis under surveillance. Her character gets carsick during a chase. Lucy's so dopey she holds her breath to get rid of the hiccups until she nearly passes out.
Her grossest scene comes off-camera, when Lucy goes to the bathroom while Cameron and Drew discuss their plan of action. Lucy's sounds of flatulence and other bathroom noises are so loud, the others have to raise their voices.
The unflattering depictions were not in the original script, Giancola said. Smith and her son added them to liven up the humor of her character, he said.
"All the shots at her personality come from her draft of the script," Giancola said.
"Nobody told her what to do, that's for sure," said co-star Jimenez. "Everything you see is her choice."
"Illegal Aliens" includes a prima-donna moment or two for Smith, when she veers out of character, argues with the director and draws one of the movie's biggest laughs after demanding to know who she has to have sex with to get out of the picture. Male co-stars rush in with their hands raised.
In reality, Smith was anything but a prima donna, coming to the set focused and ready to work, Jimenez said.
"Based on her history that everyone knows, that is common knowledge, we weren't sure what we were going to come across," Jimenez said. "So we were very surprised in a nice way."
Smith and her son were among the top investors in the movie, which cost a bit under $3 million to make, Giancola said. Plans to release the movie were delayed after Daniel Smith died from a drug overdose last year.
After Smith herself died in February, screenings of "Illegal Aliens" were canceled, but the filmmakers eventually went ahead with plans to release the movie through MTI Home Video, which already had negotiated for the rights, Giancola said.
Smith's share of the profits will go to her infant daughter, Dannielynn, Giancola said.
"My intention was to distance the movie as much as possible from her death so people could laugh," Giancola said. "That was her intention. That was Daniel's intention — to get people to laugh. Some people are making the wrong assumption that we are trying to capitalize off her death. But she and Daniel were investors in the movie, and we're basically just fulfilling hers and Daniel's wishes."