Memento Mori in its pure form! In GUGU, there is place for fun, but also for some more philosophical elements. Dark, greyish colors emphasize the seriousness of the situation and the skull... appearing as if of nowhere, suggesting still life. Has it gotten grave? Relax! It is just us, and skulls have been one of our favorite motifs for a long time now. There's nothing wrong with the world, don't worry.