Topps Star Wars Galaxy Series 5 Artist Sketch Card
I chatted with artist Jamie Snell earlier this very evening after he shared this image with me. Jamie explained how he once had taken a course in college dedicated solely to marker rendering--a valuable skill that has served the artist well.

We also spoke about stylization as a departure point from sketching established promotional images. With skillful stylization portraiture becomes imbued with the artist's own personality. Jamie, thank you for sharing this with me.