The girl shows them the clock! Its innards are clockwork, though the blocky battery that also weights its base powers the spinning of the first gear rather than there being any winding mechanism, and she is adding parts to make little figurines of fish spin in place on the surface on each hour.

Isabella refrains from complimenting her on it, though she does smile kindly. People are always giving angels gifts, and this only becomes more likely if they compliment relevant objects.