Yes it is. Skintight suit and enhanced curves (BoxBox confirmed). Sex sells. Why is one of the original things of the universe have to be the way she is? I got 0 idea other than sex sells.
Search up "Order Knight" on google
http://img08.deviantart.net/629b/i/2014/240/2/b/knights_of_the_order_by_johnsonting-d7wzccf.jpg
by St Theo
It's not even the same genre as Riven but I could imagine any warrior on Order's side would take a more formal approach to their attire. But once again sex sells.
Like when I'm thinking about Order I'm just thinking their going around having a bunch of of orgies. Mind you, knights did the same but at least they were not as open about it as to dress like sluts on the battlefield :s