While this arrangement offers flexibility, it also means that "4K" and "UHD" won't necessarily guarantee better picture quality any more than "1080p" or "HD" do today. A highly compressed 4K signal could, in many ways, look worse than a less heavily compressed HD signal.
In other words, streaming 4K might look worse than current 1080p Blu-ray, depending on how much compression is used. With Netflix now streaming "House of Cards" in UltraHD at 15.6 Mbps, initial indications speak of 1080p Blu-ray looking "cleaner," confirming some expert predictions. The likely reason? 1080p Blu-ray has a lot more bandwidth to devote to video than online streaming, more than compensating for the discs' older compression scheme.