TEXT
Here's to the crazy ones, the misfits, the rebels, the troublemakers, the round pegs in the square holes... the ones who see things differently -- they're not fond of rules... You can quote them, disagree with them, glorify or vilify them, but the only thing you can't do is ignore them because they change things... they push the human race forward, and while some may see them as the crazy ones, we see genius, because the ones who are crazy enough to think that they can change the world, are the ones who do.
"A square peg in a round hole", or "the round pegs in the square holes" as used in the advertisement, are examples of idiomatic expressions. Alike these expressions, the meaning of many other English idioms are easily understood just by analysing their words and establishing a relation with the context in which they are inserted.
Bearing this in mind, what does the expression "the round pegs in the square holes" mean in Text?
It means a person who follows the rules of the place where s/he lives, works, etc.
It means an unusual person who does not fit into a particular place or situation.
It means that it's not advisable that people who present "round" behaviour interact with people who present "square" behaviour.
It's used to refer to people who see things as most people do.