As evidenced by 2018's "Bumblebee," the Autobots have been on Earth for a while with the mission to stay hidden until they can find a way to get back to Cybertron. They obviously don't reveal their true forms to just anybody based on Optimus Prime's reaction to seeing Noah when Mirage brought him to their meeting. Since they've had to be lowkey all this time, it begs the question of how Mirage has learned so much about American pop culture.
At one point, he references the Tom Hanks film "Big," and when the topic of "E.T. the Extra-Terrestrial" comes up, he says, "E.T.? That little ugly guy in the basket?" He also directly quotes "Dumb and Dumber" with "I like that. I like it a lot." But he's not just a movie buff as he brings up Wu-Tang Clan and seems genuinely distraught at the thought of Marky Mark leaving the Funky Bunch. These references likely exist to take advantage of the fact the film is set in 1994, bringing up things people in the early '90s would talk about.
But it's not like Optimus Prime or Arcee (Liza Koshy) constantly talk about pop culture. They've naturally stayed hidden all this time, and Mirage should have done the same. Even if he knows about Wu-Tang from listening to the radio, he can't exactly stroll into a Blockbuster to rent "Big." And he must have seen it as opposed to hearing someone else talk about it because he uses it in context. So what happened here?
