Nah, I know what a flat bar is

These have the "curvy" bars and the handle grip ends point back towards the rider - I'm sure there is a proper term for them. They aren't all that wide as far as I could tell, certainly seemed narrower than the trekking bars I have at home.

And just to make sure we are all on the same page, by mixte frame I mean the step through style.

The only thing I've seen locally which remotely resembles these bikes is that clunky Giant thing that has the ultra-wide seat and looks like it is designed to take an electric motor.