Renault were trying these winglets on the frontwing in testing recently.
Interesting the way the winglets are mounted on the endplates so smoothly, reminds me of that one aircraft (can't remember it's name).
In the aircratft the solution reduces vortices (drag) I wonder if the idea behind that mounting is similar.
The actual winglets seem to serve as downforce generating elements(airfoil shape), with that slight slppe at the end directing the flow better.
For some reason they remind me of the Toyota version of the original Jordan "infront-of-the-sidepod-intake"-winglets.
edit: forgot to implement the picture