We'll stay on the Artistic interface and add another effect to the previous one, so that both will be applied together. What else could it be but Rough Pastels?
First, click the indicated icon on the lower right, then select the Rough Pastels preview. The "broken", painting-like forms now show a rough pastel effect. Stroke Length and Stroke Detail are the two settings you should alter. Experiment with them until you find which combination produces the best result for your picture.
Texture specifies the canvas type for your imaginary painting. We'd suggest leaving it on Canvas. Other settings are optional as well. Scaling sets canvas roughness, and Relief controls how much this roughness affects the photo. Setting it to 0 makes the pastel effect vanish. Be sure to use a higher value!
The Light menu specifies which direction the light falls on the drawing, which slightly affects its look. You can also choose to Invert the bulges of the canvas texture.