Your devices reach each other
Machines signed in to your account can reach each other. With a subscription they can also send internet traffic through CryptoMesh exit servers, and any account can use exit nodes it runs itself. The network policy CryptoMesh generates does not grant other customers' accounts access to your machines, even when two homes use the same 192.168.1.x addresses. CryptoMesh operator accounts are not exempt: they can reach only CryptoMesh's own servers, not your machines or your home network.