The empeg doesn't have "lights". It has a single, 32x128 Vacuum Fluorescent Display (VFD).

That aside, what one can do, is build a separate display as shown in the photo you posted, control it with something like an Arduino or RaspberryPi. Then connect that to the empeg using Ethernet, and have the separate display repeatedly fetch the empeg's screen contents and redisplay them on the custom LEDs.

The empeg Web Lite interface as well as the Android app both do something similar, so those could be used as reference code for a starting point. It should be pretty simple in the end.

Cheers