I went to DDP last time i was in Seoul and was kind of skeptical of its 'spaceship' appearance from the outside. It was only after climbing down to the plaza with the beautiful bridge that cuts across it and the structural elements that support it, I felt that the building was truly one worth visting .
From your photos it seems that its so much more beautiful during the night. I've put it down on my list for next time!
Hahaha, Yes, night view of the DDO is essential in visiting Korea