If the game detects that you are playing an illegal copy after a Sim finishes any action that uses the mosaic censor, instead of it disappearing as normal the mosaic will not only remain there but will grow until the entire screen is nothing but pixels.
In The Sims 4, if a Sim is pregnant the player can influence what gender the child will be. If the pregnant Sim eats carrots or listens to alternative music on the radio, the baby is more likely to be a boy. If the pregnant Sim eats strawberries or listens to pop music on the radio, the baby is more likely to be a girl.
If a Sim interacts with a certain tree, they will eventually be able to explore it. This will unlock a secret area called "Sylvain Glades".