Look for mirrors and turn signals in the pics, rather than just a headlight. KTM's site can be a little tricky since some of their models are street legal in Europe but not here, and they don't always show the right picture for your country. Of the current lineup, I think only the EXC models are street legal.
The Japanese manufacturers sites are clearer - everything street legal is typically listed in their Dual Sport section, rather than in the Off Road or Competition sections.
If you're looking at used bikes, you want to see "blue plated" in the description somewhere. You used to be able to convert dirt bikes into street legal bikes, so you can still find some interesting bikes that were never street legal from the factory. The MTO no longer allows this though, so you won't have much luck trying to convert a green plated (off road) bike to be street legal.
