Ensuring "the sequel was different from its predecessor" meant giving the film a unique look. Parker Finn wanted to depict a "glammy, shiny, very fun pop star's world," but also make it feel "very cold, frigid, threatening and almost alien." This meant avoiding the usual horror settings of cold creepy basements and shadowy attics. Finn said he wanted to find fear, dread and unease in an unexpected environment.
The opening scene for Smile 2 was filmed like a one-shot sequence but was in fact several takes digitally stitched together. Kyle Gallner performed his own stunts for that sequence.
The line "This is gonna ruin the tour" was actually a joke that was said on set which writer/director Parker Finn wrote into the script.
Naomi Scott said she modeled Skye Riley after Lady Gaga. Furthermore, when she's scrolling through her contacts to Gemma's you can see "GAGA" above.
Parker Finn worked with surgeons to create accurate scars on Skye's body, basing it on what victims in severe car accidents might receive. The scar on her torso is called an exploratory laparotomy, which is used to examine the internal organs for any damage.