There is no rule such that the bathroom lighting should be provided only in the ceiling or is better if it is provided at the sides or on top of the mirror. One has to fix the bathroom lightings according to one's taste and the mood that he or she wants to bring into the room. Even for a small bathroom, people, these days, go for two or more lighting fixtures. Thus, lighting is the most important factor to be considered in any modern bathrooms.
The mirrors in the bathroom should reflect as much natural light as possible, also, artificial ones, if placed in front of windows, will reflect the light giving the impression of a wider space. The bathroom light must be clear, with controlled intensity and not bright. What ever lighting you choose, it must work with the furnishings, mirror and other decorative pieces placed in the bathroom. A classic style bathroom must have mirrors with elegant frames and shaded lighting bodies . For modern design choose mirrors without frames, spots placed strategically so that the light is not too bright.
Spot lighting such as that offered from recessed ceiling lights, usually LED or halogen, can look incredibly stylish, and helps focus more light where you need it. But for lighting near bathroom mirrors a soft, diffused effect can work extremely well, giving you a more even light.
The bathroom represents a significant, strictly functional area of the house and therefore we must give it special attention when planning to decorate, both in terms of the bathroom suite and the lighting fixtures.