pot·pour·ri
/ˌpōpəˈrē/
noun
a mixture of dried petals and spices placed in a bowl or small sack to perfume clothing or a room.
a mixture of things, especially a musical or literary medley.
Therefore, the phrase "a beautiful potpourri..." or mixture "...of differences" means that whatever this line is referring to is a pleasant mixture of many different things.
Hope this helped.