The technical stained glass term is "plating", but basically it consists of building up several layers of glass soldered one layer of top of the other to achieve shadowing and dimensions that can't be achieved with just one layer of glass.  The pattern actually consists of 5 patterns that are built one on top of the other. The shadow on the wall is done by soldering a stained glass piece of alternating grey and clear glass under the white glass.  Check out www.glassplating.com for the Barry's patterns.