I have to say for all of the thousands of hours I've spent perusing Houzz, I'm stumped; I don't think I have ever seen this - you mean there is no carpet over the risers at all?

How odd. Back in the 70s and 80s I remember seeing stairs with wood risers and carpet on the tread and wrapped around the bullnose, somewhat like this photo:
http://diymoderndesign.com/wp-content/uploads/2009/05/bamboorisers2_c.jpg

I didn't think it looked particularly good, and besides that carpet wears very poorly on stair treads, so I can't think why it would be recommended. I have seen some examples of tile risers with wood treads. Is there a particular reason you're thinking of carpet?

And of course, after I hit "enter" I found an example of carpeted treads with a decorative riser that is something like tile:
http://www.decorativestairs.com/images/OSB-DesignsB-A.GIF

Still can't recommend it, but good luck!