This was a prototype for the Radiance festival of light which was held in Glasgow for a few years until the council pulled the plug on the funding due to financial politics. The festival itself ran over a weekend and was basically a series of illuminated art exhibits spread over the city centre in quite random and sometimes hard to find places. Part of the fun of the event was using a map to find the features and then suddenly turning a corner and finding them in all their luminous glory.
The original plan was to have these panels mounted as armbands or elsewhere on clothing to allow the public to identify the marshalls or guides that could help guests find the more tricky locations.
If they had gone ahead the software would have been changed to include very bright (unmultiplexed) random sparkling on the panel, and some animations that represented specific art pieces.
The circuit is very simple. Just a PIC16F627A microcontroller and two SIL arrays of 100 ohm resistors to drive a 5x7 matrix of 35 warm white LEDs. I wrote the software in machine code (assembler) to allow for very fast multiplexing and leave plenty of room for effect routines.