Joyful and relaxed. The entire poem has a laid back vibe and when he describes the beauty in everything he has an awestruck vibe.
They are more interesting because they are abnormal signs of beauty. People are attracted to different than the norm things and when the beauty of salt stains is brought up, it confuses the readers.
It further enforces the fact of beauty. Using more similes makes the reader realize how beautiful the world really is.
The narrator appreciates the little things in life and can find beauty in the smallest things.