Multi-signature, or multisig, decentralizes control and prevents a single point of failure. In essence, this means three separate developers will share responsibility for the GMR contract (via our timelock contract), with each developer required to sign every call made on the contract.
Multisig also protects investors from potential risks associated with any loss of control over the deployer wallet, as there are essentially three deployer wallets.
Using a multi-signature structure, the three developer wallets are reduced to a role of a "proposer". This means any single developer can propose a call on the contract but will be unable to execute the call without a successful two-thirds majority vote - with the call execution then being delayed as per the Timelock contract.