What would you do??

Recently I was working in a significant needs classroom, I had an issue with the way a staff member engaged with a student. The student was having a difficult time during the circle time activity. This staff member was asking the. student to sit at desk to gain a reinforcer. Instead of making the statement "at your desk" then repeatedly engaging with this student with this same statement over and over again. The tone and statement to "sit at desk" was more aggressive over the continual demand to sit at the desk. What would you do to help the staff member and the student?