Something along the lines of "for when being the size of small moon just won't cut it" seems to apply to the largest spaceship. Oh, and thanks for finding the artist.
Either this artist doesn't know what he's doing or this spaceship is so fucking massive that it has stars in FRONT of it. Jesus Christ.
I believe the "stars" are just lights coming off the ships exterior. Still, this image still has a lot of WTF the longer you stare at it (in a good way).