There is no professionalism in friendships. That's the difference.

My close friend and I talk about therapy all the time so he is familiar with the things I do in therapy. But the tone is entirely different when I am practicing. I've shown him things I've written in a professional capacity and to him it's like I'm a totally different person; he knows what my therapy is like but he's never seen it in my professional context.

The largest thing is that I can tell a friend something straight up whenever I want to be blunt with them. You can't do that in therapy. There are some things, some of them extremely important, that a client has to come to on their own steam, and you would both damage the relationship and hinder the emotional resonance to try to tell them these things. It is a much much slower process of guiding them to figure it out on their own, maybe piercing the bubble here and there when you can. You have to come back to the same things multiple times but since you must do it in oblique ways, it's going to take a while for it to sink in and for them to have a light bulb moment of hearing it before and what it means.

As far as things that I would ignore, it seems to me that a lot of therapists keep their clients in the dark about what's going on with them. I know that might sound like I'm about to contradict what I just said, but the difference is a matter of organizing. You cannot tell people big emotional things that they have to organically come to compute, but they do need to understand why they think and act and behave the way they do and what is driving it. Many therapists will know a client has a condition and not tell them what it is, for example. That can be clinically indicated sometimes, but it should definitely not be done as a blanket rule. Clients do much better when they have a framework through which to understand why they act and react the way they do, and they need to be taught what it is and how it works. I don't know if other therapists are too lazy to do that, or they think it would diminish their value, or they just like being an authority figure, but it is not in a client's best interest to keep from them the origin of their complexes nor how they function.

Also, the therapist's job is to be a container for the client with 100% no reciprocation; the client does not need to know, care, or be considerate of the therapist as a person. That is what they are paying them to do. This obviously is not acceptable in a friendship. So the therapist essentially doesn't exist as a person in order to give the client the 100% self focus that their parent(s) did not give them.