Disco dancer

A man in a vest stands with his back to the camera, wiping a green chalkboard with a red eraser, while two other men in vests sit in the foreground facing him. The man at the board repeatedly moves his arm to erase, then steps back, while the two seated men remain still, observing. The scene takes place in a classroom with a pink wall, framed portraits, and a wooden triangle protractor on the wall.