Beauty is something that can't be explained. We see it everywhere. Flowers are beautiful. The stars are beautiful. Creation is beautiful and so are things that are man made. But is that really what beauty is?
No. Beauty is definitely outward, I mean we see it everywhere. But what about the beauty of a person? A person can be absolutely beautiful on the outside but without value and virtue that person becomes very ugly very quickly. For instance. A woman can see a man for the first time in her life. He is a very good looking (beautiful) man. But he's hiding something. He's hiding the fact that he is a terrible person. He's lazy. He's a horrible horrible person. She finds out very quickly and when she does, she sees that that outer beauty the man has just deterioriate in a flash before her eyes.
Now lets use another example. Another woman sees a man who is unkempt, has long matted dirty hair, numerous scars on his face, skinny and mal nurished. But he isn't hiding anything. She looks past that outer "ugliness" and sees that he is nothing but good to her. He treats her like an angel. A goddess. She is his queen. And on top of that he is a follower of Jesus Christ who knows beauty better than anyone. When she discovers all of this, she sees his matted hair disappear, his scars become fresh pure clean skin, and his outer ugliness becomes nothing but imminent and forever lasting beauty.
THAT is what beauty is. So in answer to those questions, yes, beauty can be only skin deep, but REAL beauty goes to the deepest part of a person and deeply enhances that on the outside.