You could identify it as ssh vs SSL because they have different unencrypted headers. So systems which check that you are speaking SSL on port 443 would block ssh.
With HTTPS you get a handshake Client Hello packet sent in the clear, which has a TLS version identifier and a plaintext session ID among other things. With SSH2, you get a literal "SSH-2.0" as part of the protocol identifier which appears before the key exchange.
