Well, the design of the model certainly doesn't follow what we recognize as Shenmue visual style (too "chibi-styled", one could say), but I don't think there are many characters from the first batch of Dreamcast games who dress so similarly to Shenhua, so it's possible that it could have been a very early model or just a placeholder to represent Shenhua at some video game fairs.

After all, many 1999 game fairs, even as late as September, showed Shenmue builds with content which did not appear in the final game. See for example this picture from the 1999 Tokyo Game Show, in which we can see a Shenmue title screen which was very different from the definitive one.

http://oi60.tinypic.com/mvkltx.jpg