Why does he never show his face?

Ever since I started reading ATWQ, I’ve noticed that you see everyone’s face (Moxie, Ellington, Stew, Pip, Squeak etc) but you don’t see Lemony’s. I know ambiguity is a common theme in ASOUE and ATWQ, but is there a lore kind of reason why Lemony never shows his face (or to be specific, his eyes) in the books? I’ve only seen his eyes once in Who Could That Be At This Hour, when Theodora is waking him up, I think, but apart from that I’ve never seen his eyes.

TL;DR: In ATWQ, why does Lemony never show his eyes/face? Is there a lore kind of reason for this?

Btw, if this post is better suited for r/ATWQ, please tell me.