Just like everything in the movie, all the foreshadowing they place is AWESOME!
- Near the very beginning of the film, during the establishing shots of the city, look at the Lord Business billboards in the background; phrases such as "President because he says so" and "What part of 'No' do you not understand?" can be seen on them. This would indicate that Finn and his father have had LEGO-based disputes before.
- During President Business's speech, he tells the viewers to follow the rules "or you'll be put to sleep". While this sounds like a Deadly Euphemism, it's actually another nod to Finn and his dad. One type of punishment that parents sometimes use on their kids is sending them to bed early.
- Noticed the rubber-band and lollipop wand Vitruvius has? Those, along with the "relics" Lord Business collects, suggests that the LEGO World takes place somewhere very close to us humans.
- The first time in the film Taco Tuesday is mentioned, Lord Business says all the citizens will receive "a free taco, and my undying love!" At the end of the movie, Finn gets both from his father.
- When they enter Emmet's mind, Vitruvius mentions "The Man Upstairs" and Emmet thinks of a construction of him, shaped like a giant human hand. This is somewhat negated by a Freeze-Frame Bonus earlier on.
- Take a close look at Lord Business' helmet and cape. It's a red tie, just like the one Finn's dad wears.
- Several sound effects, such as the noise of a plane taking off, are made up of mouth voice. You'd think it's just Played for Laughs until it is revealed that the entire movie is set within a real-life kid's imagination while playing with his father's LEGO set effecting a whole 'nother world. This is further elaborated upon when Vitruvius is a ghost; he is obviously covered with a LEGO blanket piece to make him look like a ghost, and he is obviously dangling by a string.
- In the opening scene, after he receives the prophecy, Vitruvius insists that it's true because it rhymes. His defensiveness about its veracity makes more sense when you realize he made it up on the spot.
- Two things pointing out that Emmet is just viewed as a rather bland fellow by the others: firstly, the people that he speaks to on his way to work never actually refer to him by name, instead using various forms of 'you'. And secondly, Emmet is never in line when he's walking with the other construction workers.
- During the opening montage of Emmet's day, one of the items on his list is "Drink Overpriced Coffee". ("That'll be $37.") The name of the store he goes to is literally just "The Coffee Chain." Finn, who's telling the story, is a child who doesn't drink coffee (or spend his own money), so he has no understanding of how much a cup of coffee would actually cost, or the names of any actual real-world coffee chains.
- Cloud Cuckoo Land is one giant foreshadow. Everything shown within that world, including all the mishmashed types of Master Builders that gathered and the Uni-Kitty's speech about rules, implies that there was a reason it was different from the other, more ordered, parts of the world — a reason which necessitated its complete removal from the universe.
- Emmet's encouraging of the Master Builders to work together, and their difficulty in doing so at first. It's difficult to get different mindsets to meet in the middle, after all.
- When Emmet touches the Piece of Resistance, he falls unconscious and is treated to a vision. A flash of the vision briefly shows Finn's covered face and hand, a silhouetted man opening a door, and a cat poster. Finn's voice can be heard telling him that it's his turn to be the hero. He also sees the Believe cat poster. Also during Emmet's vision, there's a shot of Emmet falling down a long, multicoloured tunnel.
- Everything Is Awesome. The lyrics are one giant spoiler for the movie and the ending!
- More subtle, when Batman and Emmet are discussing the plan:Emmet: Batman, when we get into this room there are gonna be audio sensors everywhere. We can't make a sound.
Batman: Don't worry, Dad, I read your dumb instructions. Stop yelling at me!
- One not connected to The Reveal: the compartments in the double decker couch used to hide our heroes are just like the smuggling panels in the Millennium Falcon.
- After the movie's opening prologue — the only part of the film that doesn't involve Emmet in any way — the title card says "8 and 1/2 Years Later" before we're properly introduced to Emmet. It seems like an oddly specific length of time, because it's a hint that Emmet is a stand-in for Finn, and the movie is a metaphor for his life. 8 and 1/2 is Finn's age.
- In a similar vein to the aforementioned billboards, Lord Business' instructions for being liked and fitting in include things like "Always smile", "listen to popular music", "return compliments" and other things of that nature. In short, all things that a father might tell his son in an effort to make him fit in better (and in the case of Finn's father, probably based on his own implied struggles to fit in.)