Scattering on the edge

 

I had a look at the sign above the bar. The bottom is lit up and the inscription but not the main front of the slab. The light was shining vertically downwards from the top. I think that the light travels straight until it hits an edge and then is scattered so that some of it is sent in the direction of the eye. It was too high up to inspect but if that explanation is correct, the name must be engraved into the slab so that it presents an edge which scatters the light.