Numerical analysis of the images in visible light from the JET tangential camera show that the ELM events are characterised by impacts on the low field side components. The increase of emission is not restricted to the components closest to the plasma. One finds also that the deposition on the low field side components does not exhibit any poloidal or toroidal symmetry and varies from ELM to ELM. Conversely the increase of emission on the divertor baffles, or the top protection tiles, is close to axisymmetric.