Tonsil stone??
This is a strange one. It looks like a tonsil stone, but it is poking through the back of the soft palate into the post nasal space. So not really that close to the tonsil. Which means some tonsil stones don't arise in the tonsils at all. That's why it's always necessary to have a good look with a high definition scope as in this case.
My stones did occur all over the crater like surface of my tonsils. Laser surgery from you has meant that in the past 6 months since the procedure, I have had only one tonsil stone issue!