Alice was seated quite at the end of the gallery, and Kate's chair was at her feet in the corner. When Alice and Kate had seated themselves, the waiter had brought a small table for the coffee-cups, and George had placed his chair on the other side of that. So that Alice was, as it were, a prisoner. 
Alice was seated at the end of the balcony, and George sat at the other side of the small coffee-table, so that Alice was, as it were, a prisoner. 