- When the film's logo is being built, a cat can be seen in the first few seconds standing on a few LEGO blocks.
- When Lord Business is seizing the Kragle, you can see some robots laying a ruler down on the ground over the gap between them and the platform the Kragle's on, presumably using it as a bridge.
- A background minifigure in the coffee shop wears a Fabuland shirt — a theme that was discontinued in 1989. Another wears the stylized "B" logo used in the second-series Blacktron sets. Fabuland also shows up in the "Other Lands" section of Wyldstyle's Info Dump.
- Road signs point to Paradisa, Heartlake City (from LEGO Friends) and Century Skyway (an airport set from 1994).
- The laser in the melting chamber is a laser pointer.
- The old timey time board in the Wild West scene has "Copyrighted by Octan" on it.
- When Vitruvius is introducing his fellow Master Builders, pause when he introduces the Mermaid. One of the Master Builders in the background is Johnny Thunder.
- Lloyd Garmadon AKA The Green Ninja is also present, and can also be spotted in the Think Tank and in the Battle of Bricksburg.
- Several themes are lumped into the "other lands" category and flash by briefly during Vitruvius' earlier info dump, including Mata Nui.
- When one of the pigs falls off the broken railroad bridge, it turns into sausages when it lands.
- During the meeting of the Master Builders at The Dog, the tracking device on Emmet's leg can be seen in a few shots.
- When Emmet touches the Piece of Resistance, he falls unconscious and a flash of the vision briefly shows a silhouetted human man opening a door.
- The other signs for Metalbeard's "Rules of the Sea" include: "Never put ye hand in a clam's mouth", "Always abandon a lost cause", "Never release a Kraken", and "Never wear a dress on Tuesday".
- Blink and you'll miss it: When Vitruvius and Wyldstyle are entering Emmet's mind, quickly pause at the bright flashing lights to see Wyldstyle's, Emmet's and Vitruvius's heads interchange with one another.
- When Metalbeard transforms into a singing robot on the ship, look closely when it cuts to Emmet to see Uni-Kitty's face of disgust.
- During Wyldstyle's backstory Info Dump, she mentions that all the realms were connected and people could build whatever they wanted. This is represented by two minifigs of Cleopatra and a wind-up robot building something, before Lord Business' walls separate them. Fast forward to the end, after Lord Business completes his HeelFace Turn and the realms are saved, and you can see Cleopatra and the wind-up robot dancing off to one side of the heroes.
- When The Man Upstairs is Kragle-ing everything, one of the things he does is Kragle a pair of pants onto the actor from Where Are My Pants?
- Among the other worlds we see when Benny finally builds his spaceship is an outer-space one with two astronauts that just happen to have no-gleam eyes like Emmet and Benny. Which may raise some implications.
- Another blink-and-you'll-miss-it moment: during the fight scene in the melting chamber, quickly pause when Wyldstyle hits a table. You'll find a "Melting Room Schedule" that includes events such as an "orange juice break" and "Frank's Birthday Party," as well as the notes "Don't forget to clean the laser!" and "How about YOU clean it?"
- During any scenes where a character is moving around quickly (e.g. the scenes when Wyldstyle build the motorcycle in the alleyway and Benny rapidly builds his spaceship), at certain times the characters get motion-blurred into plain LEGO bricks, in a creative use of a smear. Some good examples can be seen here.
- During the end credits, an Academy Award and Catwoman's mask can be seen on the conveyor belt. The reason for the Oscar should be pretty obvious while Catwoman's mask appears because Chris McKay, the Animation Supervisor whose name appears just before the statue and mask, is a huge Catwoman fan.
- When the group arrive at Cloud-Cuckoo-Land, Batman says "I hate this place". One initially presumes he's referring to the sickeningly sweet colours and mood, but then you notice that he's being harassed by a clown and a guy in a reptile costume note .
Freeze Frame Bonus / The LEGO Movie