Colonists will watch TV, relax socially, or eat using the Grand Meditation Throne. This isn't too strange (even though they don't own it).
What's odd is that they will do this with any of the 6 tiles acting as the chair, and even still gain comfort from it that way. I even had one pawn fall asleep on the edge of the throne (he didn't mind it so much).
Thanks for the report, are you using mods at all? Can I get a save of this behavior as well?