[Tanasinn]

The 'Giant' prefix seems intended to make every floor of a black door larger, but only makes the very first floor larger than the standard 2x2 layout. This is best seen in castles, where every floor past the first is the same singular-room layout. This has been the case since at least January 2018.

To replicate, enter any 'Giant' prefix black door, and go down a single flight of stairs.