No I pointed at where the Egg Elite spawns. It's proably just a lighting glitch but I will be investif=gating more this weekend now I know how to get to the high tower on solo.
Go into the cave area where the core is protected by the energy shields. Go upto the door at the top and look through it. I though it was a reflection to start with but there is nothing to reflect what I am seeing.
Yeah, I think I interpreted your post wrong when I initially read it. I didn't realize you were behind the wall. For the light, it turns out that it's just the sniper beam reflecting off of the wall. You can also get that effect by standing next to any wall surface. In your instance, it was the invisible wall barrier.
I looked at that door in the cave area and I did see another intact core. I have a feeling though that it's just a permanent reflection. If you look at the small blue triangle that's next to the core, you can see the rocks sitting by it have the same pattern as the ones in the reflection. There's also a bluish reflection on parts next to the door that are opaque.
I also looked at the other similar doors on the map and they all have some type of weird reflection in them aside from the ones in the caves. The one by the Ultra Ghost looks like it has a core area in it, but it only contains the floor section of it. The intact core reflection could be something to look further into though as it was the only one with a reflection that was the core itself and it was pretty clear and detailed.