Japanese artist Shunya Yamashita, who has been doing illustrations for Kotobukiya's fancy "Bishoujo" line of Tekken figures, has been a little busier on the project than first thought. In addition to doing pictures for the figures actually being made, he's done them for almost every member of Tekken's roster.
While there's the chance these are concept images for a never-ending line of Tekken Bishoujo pieces (especially since the images for the figures shown so far are in the same poses), given their cost and the prominence of the franchise, that would be a bit of a stretch. They're likely just sketches seeing which characters could work as figures or, if they couldn't, just how cool they'd look if the care/money was actually there.
You can see the entire collection at the link below.
Tekken Tag 2 - New CGI Renders & Character Illustrations [Fighter's Generation, via Plastikitty]