What's Inside

What's inside matters.  We have so many sayings and metaphors reflecting this idea.  "Don't judge a book by it's cover" etc. 

A cake can have the prettiest, best-looking icing in the world, but if it doesn't taste good, nobody will eat it, and ​no one will remember.  Don't allocate the majority of your time making pretty icing, instead, bake a damn good cake. 

We remember what's inside, the frills are literally just the icing on top.