you have to interact with the chairs in a specifical order, that's indicated by the line on the ground
sorry, I've read right now.
Anyway, if you still need it... You have to follow to interact with the chairs following the line inside the circle. First interact with the chair at the beginning of the first segment, then with the chair at the end of the first segment, then follow the second segment and so on, until you interact with the chair at the end of the last segment. Sorry, i don't know how to be clearer than this