Don't you ever watch movies about programmers? That's exactly how it works. The protagonist looks briefly at some code before declaring "Oh wow, this guy is good." For added realism, he should be typing the entire time.
You don't ask to see the code so you can identify the really good places, you ask so you can run away from the really bad places. It's the flip side of employers asking for basic coding tests: it's not there to tell you how good the good guy is, it's there to get rid of the guy with the great-looking CV who can't write "Hello, world".
