It isn't weird, all cats have that

Edit: quick search says it is called a cutaneous marginal pouch

Edit 2: as someone else said, all domestic cats have it (I should have said this from the get go, I have no idea if mountain lions have it. But mountain lions are very beautiful cats. Big paws. Huggable looking. Not advisable to actually hug.)

That's where all your "nos" go

Better to hear you opening the treats with!

I always figured it helped the ear move better, their ears move in all sorts of directions and having a thinner single flap of skin would tear easily. This evolutionary direction let's it move and be two layers that can move and flex without tearing as easily as one.

Dogs have it, too. It was an especially favored location for ticks on my dog Ellie Mae before she passed. Had to check it after every walk

If you pet the cat, it'll temporarily change the shape of the pocket. Don't even have to touch the ears for this to work.

"earlobe"

its huge!

https://www.tt.site/t/ZTfNt1vq5/