When he goes to Earth, the Lion uses an enchantment that makes him appear to be a human being. I assume that the enchantment actually transforms him into a human but it’s possible that his human guise is merely an illusion. Given that a human and a giant lion will fill space differently, a physical transformation seems more practical but I don’t know for certain which it is. I’ll have to ask Steve about it sometime.
That is one snappy dresser. Also, I think you’re right. At some point, he’d have to interact with an object or a person, and everything would just be wrong.
It would make him really difficult to sneak up on. There’s be all that invisible lion butt in your way 🙂