Why did Leonardo da Vinci create the technique known as sfumato?

I’m the marriage of giovanni arnolfinj and giovanni cermani painted by jan van eyck the symmetry we may observe is primarily symmetry

For each of the public occasions, think of a particular piece of music or a type of music that would go with it well. write your answer in the blank. example: high school graduation: “pomp and circumstance” school academic award ceremony: sport team victory rally: political rally: funeral service:

Why did the artist of the above piece use a spiral shape?