The millennial statement must function both as alien artifact and open-ended statement suitable for casual consumption and obsessive analysis. There's a deep latent desire in this self-conscious and unshockable decade to be shocked, to lose consciousness. So OK Computer appeared, and everyone got excited. Millennialism is closely related to psychedelia, not just in the druggy sense but in the attempt for total experience. The music must construct a world around you, giving you space to travel about, where you no longer think any more, just feel.
Total experience requires costumes, dressing up.
A naked song can carry emotional weight, but can't function on the total escapist level of an album like OK Computer because it can't cause the listener to disappear, can't inspire total vacancy. More than just the song itself, it's also the electronic sounds spiraling around on the fringes, the distorted tapestry of samples which creates a counter-pull to the vacuum of the song itself. Progress requires jumping into the unfamiliar, embracing the alien, stumbling headfirst into the void. It is in the charting of this new territory and the assimilation of new vocabulary that progress is made. Just as the late '60s gestated in the '50s, so the late '90s are a byproduct of the '80s.