Tathagata refers to a reinterpretation and metaphor for enlightenment. 

The Tibetan Buddhist phrase Tathagata is interpreted as signifying that the Buddha is beyond all coming and going, e.g. enlightened beyond our state of transitory phenomena otherwise known as impermanence. At the Asian Art Museum this concept was translated into a 3 hour durational performance in which Hoover and assistants carried two 7-foot tall sheets of glass depicting the seated Buddha at the moment of enlightenment.  The image image was split in half across the two sheets and the image only came together, occasionally, in moments of passing,.  They were never displayed together and had separate bases for display, one at the top and one at the bottom of the museum's central staircase.