Oh yeah headcanon I've never shared on Tumblr before!
I think Gricko really IS symmetrical, at least by goblin standards. I think Goblins have extremely variable nose, chin, and ear sizes, so Gricko's features are actually really nicely balanced! This makes him more attractive to goblins--and, because his features aren't wildly sized, attractive to most other races as well
Other goblins--USING PIXEL TOO EVEN THOUGH SHE'S A GLOWBLIN--Showcase what it looks like to not be symmetrical, which is extremely common and nothing to be ashamed of.
Pixel would probably be considered more conventionally attractive than Skrimm, because two of her major features are the same size! Not to say skrimm is unattractive, he's just not gonna end up on any goblin magazine covers.