Dinosaurs are part of the tetrapod clade, so I never expected "four-winged" to mean anything other than that the hind limbs and forelimbs are both feathered and used for flight. That's what the artist's conception based on the discovered fossils shows.
Oh wow. I think I need more coffee. The first few times I looked at the artist's rendering, I swear I thought it was a 4 winged, two legged animal. But you're right, they rendered it as a tetrapod.
The drawing is very confusing. It looks as if the back wings are just obscuring clawed legs rather than being the legs themselves. I had exactly the same thought as you and came here to comment the same thing.
