Drag the orange square until the mouse is outside the right side of the black square but the edge of the orange square can still be seen, then release it.
Without passing over the black square again, move the mouse to the pink square.
Drag the pink square onto the blue square and release it. The drag placeholder should disappear (either when releasing, or when passing the black square), and the mouse cursor should return to normal. Fail if the pink square does not immediately respond to the drag attempt.
Without passing over the black square again, move the mouse to the orange square. Fail if the orange square moves.
Drag the orange square onto the blue square and release it. The orange square should disappear, and the blue square should turn yellow. Fail if the orange square does not immediately respond to the drag attempt.