The LEGO Movie poster campaign appealed to all sorts of audiences, old and young. They use a lot of codes and conventions such as the title, a tag-line, the billing, and of course, the main characters. The typeface is unique to the LEGO Movie as it hasn't been used by other movie's and producers. The characters are running from an explosion, with Emmet in the front, looking quite distraught and, put bluntly, scared. All the other characters look quite serious and ready for anything, whereas Emmet looks how most people would look running away from danger, making it seem like he's just like us, just a normal person; he's just like everyone else.
Wildstyle's close-up will appeal to the female audience as she looks strong, cool and independent. She's played by Elizabeth Banks who has starred in renown films like The Hunger Games, Pitch Perfect 1 and 2 and more recently the film Power Rangers. The Power Rangers film is aimed at children as well so children may remember her name and/or recognize her voice.
Lord Business' close-up makes him appear quite menacing and frightening, showing he has a hot temper. He is played by Will Ferrell who is well-known, especially for his stellar performance in the film 'Elf'. Elf is a child's Christmas film, so people may recognize his voice and enjoy his performance in the LEGO Movie. Adults may relate to Lord Business because he just wants to have everything neat and tidy and clean, and adults may want to keep everything tidy because presumably, children leave a lot of their toys around.
Vitruvius' close-up makes him seem incredibly whimsical and wise, like most old wizard-type characters in films. His appearance is akin to well-known wizards such as Dumbledor and Gandalf and is voiced by Morgan Freeman, an actor known for playing the character 'God' in Bruce Almighty and Evan Almighty. People may just find him entertaining as he often will speak in rhyme, making his dialogue interesting and funny.
The final poster is Emmet's and it shows him with a terrified expression on his face (like seen in the full-cast poster that shows them running from an explosion, I covered this in the first paragraph). All the audience may identify with this character as he seems incredibly ordinary (except I would personally describe him as 'extraordinarily ordinary') and proves that you can do anything if you put your mind to it.
Note/edit - I'm extremely sorry this is late work; I was under the impression that I had published it even though (as I now know) it wasn't so for that I give my deepest apologies.