It would be extra cool if you used lights to highlight the bottle that is being pumped from.
One option would be to put LEDs on the shelf either behind or in front of the bottles and then light them up when the pour comes from that bottle.
If the Photon is running each of the pumps, that would be pretty straightforward to do, either with a different data line per led/bottle, or if you used a continuous strip of LEDs, by lighting up the section of the strip that aligned with each bottle.