This is actually a pretty good question. In appearance these 2 vehicles are the same. If you go to the http://www.toyota.com/compare/index.htm
l#h_overview you can compare 2 vehicle - I did the comparaison with the 2 Prius models and I see the full list of features-specs with the few minor differences - Sorry I am not able to attach that printout on this post.
You can see that the touring model offers optional equipment - for example the bluetooth whereas the other base model does not offer this option. The touring model is also a bit more expensive.