Uhh...but why would just a silhouette of Mihawk? Mihawk no longer has anything to hide except his skills. We even saw him post-war style in Zoro's training.
Unless something extraordinary happened to his visual (Like burn in face or something else) Oda would definitely draw Mihawk in there without any silhouette for extra hype.
Besides, even if we consider that white area as his eye, that shape barely matches Mihawk at all. I know it doesnt prove anything so far but hell, it was fun experimenting!