What the heck?! (T:ANE BR Class 55 with some sort if face)


Local Transition Era nut
Ok, time to build a route. 1 fresh, untouched baseboard. Where do I go from here? Simple, build track. New track was laid 3 meters above level ground, starting a 2-track mainline with a junction coming off of one side and no crossover to the other yet. Next, I put down a BR Class 55 on the mainline, 55019 'Royal Highland Fusilier'. Then I entered driver. Oh cool, a new horn! Awesome, the loco will "die" if it overheats too much or too long! But upon re-entering the cab from the front, I spotted a face, if you would call it that, on the same side, underneath the two marker lights. What in the world is this?! How?! Why?! But most importantly, how do I get it to show up?! BTW, is this supposed to be some kind of reference or is it a joke? Or is it nothing at all? Also, the face is two eyes, a sinister grin, and 2 blood trails or scars going up and down the eyes.
I've seen a screenshot of it before. Now if only I could remember where it was so that I can find it again!

Never mind; I found the face: It is on the exterior mesh for the interior asset, if that makes any sense.