That middle section of the front bumper on the mk8 Golf in R Line trim in this YouTube video is very similar to the one in the render of the Golf R.
In the video, the car has a show plate fitted that’s the same size as a Euro licence plate (ignore the fact that the plate’s not level ?). The section of the R Line bumper that the plate‘s fixed to is also narrower than the licence plate, causing the bottom edge of the licence plate to protrude into the top edge of the lower grille.
So there’s a good chance the middle section of the front bumper in the render of the R is an accurate representation of what the production model.