I think that's really hard. Personally, I would feel like a child who was being scolded and being told to go back to her seat in class. (I am sure I am projecting ALOT there, tho!) However, I have read most of your posts and it sounds like you have a really great T. My first reaction was that she could see you just fine sitting next to you...but I think if she is looking at your body language as well, then she would need to be sitting across from you. I definitely don't think she hated you being next to her!

One of my Ts has sat beside me when looking at stuff on my phone, or at a book I brought in, etc...but he has come and sat beside me. That has always made it easy because whenever we are done he can stand up and go back to his chair. (Sometimes he goes back right away and sometimes he doesn't...we do EFT and EMDR so we both move around for that anyway.)

Are you thinking about telling your T how you felt when she told you to go back to your seat? Is it logistically possible for her to come and sit by you in the future?