A moiré-effect winding assembly for an automatic timepiece movement includes an oscillating winding mass which is movable relative to the movement. The winding mass is to be mounted to rotate on an axis of the movement. Part of the winding mass forms a heavy part allowing the mass to oscillate in response to the movement of the timepiece and to the force of gravity. The assembly also includes an element that is stationary relative to the movement. The stationary element is arranged under the winding mass. The winding mass at least partly displaces above the stationary element. The stationary element includes a first relief pattern and the winding mass includes a plurality of through openings defining a second pattern, so as to create a dynamic moiré effect when the winding mass displaces above the stationary element.