For me also connection develops via mutual sharing and based on what I know about the other person. It can be just seeing how they behave and react, but for me even more exchanging thoughts and experiences, so information. It also makes a difference if I feel I have some things in common with them. If that was not necessary, we could possibly feel connected to just about anyone we are in a room with, which I doubt is the case for most people. We may ask: what is a relationship and how do we feel anything about each-other? All that can be based on information from only one person and how the other handles that information, but this is not how it most commonly works in everyday relationships. I think many people struggle with therapy exactly because it operates and is meant to be sustained in very different ways from ordinary interpersonal dynamics. I believe that T's self-disclosures, when used in moderation and keeping the client's perspective in mind, is meant to ease the development of a connection via providing information to connect with. Of course if the T does this in a way that distracts from the client and overly draws attention to themselves, then it is excessive and does not serve that role.

I think it is not easy to gauge and dose this. The same amount of information can be just information to one client but another one may latch onto it and would use it as distraction from their own issues, or to take care of the other instead of themselves.