It’s a rejection of anything falsely called a “contract” which involves aggression. The two are mutually exclusive. Contracts are voluntary. The “social contract” as commonly explained is not voluntary, regardless of its various forms.
That’s just sweeping statements. I also don’t think one should necessary connect the state to social contract theory in general.
But let’s assume there is a country club. They got premises and they got membership. They also got rules for their premises and relating to their members. Those rules can be formulated or tacit (i.e. common practices in the club). Would you agree to any or both of the following?
a) If you become a member, you are bound to the rules?
b) If you are on their premises, you are bound to the rules?