Don't know, but with a bottome like that, it better have super duper flushing abilities, otherwise, me thinks there would be decorative splatter.
According to Kohler:
With its clean minimalist design, the Purist Hatbox toilet opens the door to a new era of possibilities for making design statements in the home. Innovative tankless Power Lite® technology provides exceptional flushing performance with a .2-hp pump. A Comfort Height bowl and Quiet-Close toilet seat ensure comfort, hygiene and safety. Electronic soft-touch actuation