Why do cartographers add artistic pictures like angels, to their maps?

the protestant reformation's started in 1517, disturbing the religious and political order in europe´s catholic countries. the outcome was the european wars of religion prosecuted in europe in the 16th, 17th and part of the 18th century. nonetheless, uprisings, territorial disputes, and great power conflicts were also causes of the wars.  

it was a act of seld fesnse more over it was a peace treaty between the fogein contunries.