Some of the more inspired Björk remix work ended up on this single, thanks to the names involved. Mark Bell handled the initial mixes well enough, pumping up the orchestration on the opening "Optimism" mix and playing around with beats on the "Zip" and "Blue" takes. Things start getting really good, though, when the Wu-Tang Clan's RZA steps in with his own mix; rather than transforming the song into one of his deep, dark hip-hop movers, he keeps the strings and makes the new beats a bit lighter than usual. It's no surprise it's him doing it, but isn't RZA-by-numbers either. Atari Teenage Riot mainman Alec Empire then steps up with two sharp takes. The "Hypermodern Jazz" mix has a heavily-flanged beat and crawling bassline supporting an even more trebly mix of Björk's singing, if that's possible, and twinkly extra keyboard bits slipping up and down in the mix. The "Ice Princess and the Killer Whale" version moves completely into Empire's particular aesthetic, his trademark clattering, hyperspeed hip-hop beats appearing and disappearing just like that while frigid synth string stabs and low drone bits shoot around. Björk's vocals in this context provide the one slight hook to hold onto in the chaos, making for an excellent combination all around. Grooverider wraps up the EP with his lengthy "Jeep" mix, a fine if not terribly distinct effort, though the introduction of stronger beats halfway through helps.