Many people think Mass Effect 3's Multiplayer should have been more similar to Battlefield or Battlefront with large-scale epic battles and the like; Mass Effect: Unification does just that.
Marth realized the hex shields on Virmire weren't as high quality as they could be, so he redid them. Each one emits light.
Also note the glowing elements on the Geth Pulse Rifle that were added.
Yes we fixed the Geth Pulse Rifle, shut up about it you silly goofs. :P