Talk:Dr. Horn's Discord statements/@comment-45935703-20200601204119/@comment-24234983-20200624173801

The first cube contains entities that appears to have been set up solely for the purpose of allowing the radio message in Dr. Horn's lair to be played with closed captions.

The "mirror" Nihilanth portal and tower you found is part of the 3D skybox which makes up the sky and the geometry you see in the distance.

The cube in the next map is where the gas canister gets teleported to when you put it on the teleporter pad (it has to be teleported somewhere).

In other words, these cubes are just part of the level design and what goes on under the hood of the map.