I don't know how to define it but I know my T and I have a good connection. She's willing to get close to me and I need that so that I can get close to her. She has good boundaries but she's "next to me", not "up there" somewhere. I trust her enough to tell her everything in the hope that she can help me. We have some things in common so there was a basic connection at my first session with her. I think it's also her acceptance of me and her willingness to tell me that she likes me that make for a good connection, though I know many Ts won't tell their clients directly that they like them, but you can still have a good connection.