It's cool that one of their screenshots shows off the desktop cube effect. It's just a fun and mostly pointless thing that gives the software a bit of personality. On its own I don't think it amounts to much, but it combines with the rest of the KDE sphere to convey a sense of joy that at least for me is a pretty central aspect of open source and free software culture. That vague perception is probably not the main reason I'm still using KDE now, but it sure doesn't hurt, and it did help guide me toward KDE in the first place.