What Am I Riddles

Question: A mirror for the famous, but informative to all.
I'll show you the world, but it may be a bit small.

What I am?

Question: Something different to show every week, but I'm still the same place.
If you're eating it's probably butter that you taste.

What am I?

Question: I am the only organ that named myself.What am I?

Question: I am a small room,
but no life lives inside,
no matter what weather looms,
very cold my residents reside.
What am I?

Question: Swallowing one is fine.
Swallowing two together is fine.
But Swallow them separately and all shall fall.

What are they?