[Portal 2] "Borealis Boarding" Easter Egg ("Ship Overboard" Achievement)

I found this by myself, but later I looked more into it and found out that is a pretty old easter egg.
Let me know what should I investigate next.
#Portal2

[@markorakonjac9718]

Really quick showcase and edit was really good, saved my time watching this. See you in the near future...

[@therealfrapsed]

thank you!