Video settings I can't see my small picture, only my client in full screen

Hi I somehow chamged my settings..I used to see myself until my client entered waiting room, then once I accepted them, there was a small thumbnail of me and the rest of the screen was my client. Now the thumbnail is gone

Any suggestions? Unfortunately, I've clicked and unclicked a bunch of things now so it's really messed up. 

I'm on zoom with patients all day.

Any help would be appreciated!