There is disclosed a timepiece (40) including optical means for forming a decorative pattern, in the form of a figurative image, in response to an action by the user. The optical means forming a figurative image include an optical guide (1, 51) having two large faces (10, 11) and at least one lateral face (12). Optical extractors (19) each having at least one light reflective surface (20) are arranged in at least one of the large faces (11). A light source (8, 8a, 8b, 8c) is arranged so as to emit light in the direction of the reflective surfaces (20), via the lateral face (12) of the optical guide. Thus, each of the reflective surfaces causes a reflected light beam to form in a well defined direction, the set of light beams forming a figurative image in that direction, which can typically be selected as the normal with respect to the mid-plane of the watch.