The very common English idiom “Don’t Judge a Book by its Cover” is a metaphorical phrase which means “don’t determine the worth of something based on its appearance”. It is probably the most common expression used in English to convey vanity. It is often used in modern culture, and has become a problem for people that don’t seem to fit in. Watch these:
Ok now, let’s listen to Taiwanese Lin Yu Chun sings now on Taiwanese talent show Super Star Avenue 2010, giving his all for the $1 Million prize.
Now you know what exactly the English saying’s means.